〔原文〕通玄集云∶其补真妙理，只要心头无事，内外俱忘，一齐放下，把捉得定。阳生
子时，阴生午时，静室披衣，握固，端坐盘膝，蹲下腹肚，须臾升身，前出胸而微偃首于后。后开
夹脊双关，肘后微扇三，伸腰自尾闾穴，如火相似，自腰而起，拥在夹脊，慎勿开关，实时甚热，
气壮，
渐次开夹脊而放气过。仍仰面脑后，紧仰以闭上关，慎勿令开，即觉热极，气壮，渐次入顶，
以补泥丸，髓海。则身耐寒暑，为习长生之基。如前出胸、伸腰，闭夹脊存而升之腰间火不起，
当静坐内观，如法再作，以至火起为度。自丑行至寅，终可止。是曰∶肘后飞金精，又曰∶
抽铅使肾气生肝气也。又略昂首仰项放，令颈下如火，方点头向前，低头曲项，退舌尖近后以
柱上 ，自有津出，不漱而咽下还黄庭，是名∶金液还丹。四时不拘时候节次行此，自艮至巽而
已，晚间乃勒阳关法，自兑至干而已。
〔解说〕《通玄集》说∶“补益真气的奥妙道理并非高深莫测，只要放下杂念，使诸事不要
挂牵心头，将外界刺激和内心的欲望完全忘却，一齐放在一旁，专心调息，掌握得当，就能收到良
好效果。阳气生发于子时（23～1时），阴气生发于午时（11～13时），在阳气和阴气生发的时辰，
居于静室，宽衣解带，握固两手，盘膝端坐，下收腹肚，从容伸直身躯，使胸向前挺出而稍仰头于
后，采用此姿式，练气日久后便能用气通开夹脊双关。通关时需用肘在后腰微动三次，伸腰使内
气自尾闾穴开始入脊中（督脉），其感觉如能似火团那样，自腰而起，拥至夹脊，此时慎勿开关，
要等待时机感觉火至甚热，气壮之时，方可根据次开夹脊下关先放气过入脊中。气入脊中后仍仰头脑
后，使后脑紧枕脊柱封闭上关，慎勿让开，觉到内气如火，热极之时，方为气壮，根据次再开上关，
使气入头顶，以补益泥丸和髓海。这时便可使身体耐寒暑，这种功法是修练长生的基本功。如前姿
式，挺胸，伸腰，开夹脊后存内气，而内气升到腰间后不能起火，当静坐内观腰间（丹田）之气，
如前法再作，以火起为度。自丑时（1～3时）练功到寅时（3～5时），方可停止。
这种功法叫肘后飞金精，又称抽铅使肾气生肝气。另有一法稍抬头仰项，使颈下如有火起，方点
头向前，低头屈项，将舌尖稍向后退舐于上 ，口内自然就会有津液流出，不要漱吐而咽下，
使归还于黄庭（胃内）。这种功法叫做金液还丹。此功不受时间节气限制，可四季经常练习，每日
自艮（丑、寅）经震（卯）练至巽（辰、已）（1～11时）退出。晚间练功时又称勒阳关法，
自兑（酉）练至干（戍、亥）（18～23时）退出。
小结∶
本篇简明地论述了“周天功”的练功方法和要点，着重讲解了“收心”、“通关”、“肘后飞金
精”和“金液还丹”的练法。
1、周天功
古人把天体的营运，按方位分为365度，二十八宿。把北斗七星的斗柄沿二十八宿排列的轨道旋转
一周，称为一个周天。日月沿此循行一周亦称一周天。人身如同一个小天地，气血环行周身一度也
叫一周天。如《灵枢》说∶“人身穴道三百六十五穴会，以应周天之数。”气功家把人的真气沿经络
循行一周，称为一周天。把使真气循经络而行的功法，叫做周天功。周天功有大周天、小周天、意念
周天、丹道周天、经络周天等多种。本篇所述的小周天，即使真气沿督脉上升，再循任脉下降，成
一封闭圈。具体的路线和关口是∶使丹田真气──伸腰自尾闾穴──入腰脊正中督脉──拥在夹脊关
──待气壮后开夹脊关──使真气达上关（玉枕穴）──待气壮后开上关──使真气入头顶（百会穴）
以补泥丸和髓海──然后舌舐上 引口中津液──使真气变成的“金
液”咽下还归于黄庭胃内──最后复归入丹田──再由丹田练气进入尾闾关。这样督任两脉
便相通，形成了一个周天。在这一周天中真气要通过“三关”、入“泥丸”、“髓海”、变为
“金液”，入“黄庭”归还丹田，环循于任督二脉。
何谓“三关”及“夹脊双关”？《寥阳殿问答篇》说∶“人之尾闾，在尻脊上第三节，一
名长强，一名三岔路，一名河车路，一名禁门。其下曰关元，其前曰气海，乃阴阳变化之乡，
任督交会之处，丹书名曰尾闾关者是也。人之背脊二十四节，上应二十四气，在关在二十四节头尾
之中，一名双关，直透顶门，此即夹脊关也。人之后脑骨，一名风池，其窍最小而难开，欲开此窍，
舌柱上 ，目闭顶门，全仗神炉栗火，接续冲赴，此关乃开，此关名玉枕，又曰铁壁也。”由此
可见三关是尾闾关、夹脊关、玉枕关。本文中的“夹脊双关”就是夹脊关，又名双关，上关就是
玉枕关，又名铁壁关。该书还对开三关作了详细描述，说∶“下田三宝（精气神名曰人身三宝）充盈，
乃有无路可走之势，自然冲开尾闾，从太元逆流，隐隐有两股暖气，上肾堂过脊背……但至夹脊者，
学人道浅，宝积未富，那能一时便得直透而上，切勿烦躁欲速，惟自日日行之，意中须以心目相送，
微用提撮谷道（肛门）法，如辘轳循环，自然志至气次，时候一到，片晌之间，夹脊自开，双关自辟，
直上玉枕。玉枕一关，名曰铁壁，居头凹处，有一高骨，尤难过此，必须闭目上视，低头用意，直
透此关，上至泥丸，与神交合。此时景象，有如雷轰电掣，火焚波沸，种种形声，似真似幻，切须牢
守身心，勿惊勿喜，徐徐自定，清磬冷然入两耳，泥丸、昆仑之间，有如火珠一颗，盘旋不已，
隐现于眉间，觉从鼻内而下玄膺，仍自降入气管，乃由华盖，绛宫，直抵丹田。此时身
心乐快，难以言喻，所请乾坤交媾罢，一点落黄庭是也。”本文指出为让真气过关，须从体位
和使气壮实二方面入手，体位要“端坐盘膝，蹲下腹肚，须曳升身，前出胸而微偃首于后”，
“仰面脑后”，“昂首偃项”，这和一般方书主张正坐，身须平直，认为体不端直，则气机塞者
不同，独僻一言之家，另有自己见解。对于通过三关，主张务必使气壮实，气不壮则“慎勿开
关”或“仰面脑后紧偃以闭上关”，等待“如火相似，自腰而起，拥在夹脊，”“甚热，气壮”或
“热极，气壮”，方才根据次开关。如腰间火不起，当静内观丹田，务使火起才开关。
2、收心
就是止念，道家又称炼已。就是要排除各种杂念，使心猿归正，意马收缰，正如《规中指南
》所说∶“牢擒意马锁心猿，慢着功夫炼汞铅，大道教人先止念，念头不住亦徒然。”收心的第一要
诀为“忘记”，就是练习时要“内外俱忘”心头诸事，把它们一齐放在一旁，只有这样才能专心
守一。所以《保生秘要》说，“摄心归一，专其一处，皆可止念。”本文将收心列为“补真妙理”
是非常有见地的。
3、肘后飞金精
又叫抽铅使肾气生肝气法。《周易参同契》认为∶坎为肾，属北方王癸水，色黑，在丹称黑铅或黑
虎。所谓抽铅，《悟真篇补注》说∶“抽铅添汞，犹云取坎填离，凡进火退符，皆是抽铅。”可见抽铅
就是取肾中真水（也即真精，道家谓之金精），以济心火（汞在丹为心，属南方丙丁火），使夫妻交
媾，阴阳相济，或取肾水以涵养肝木，使肝气生发。本文讲的是抽铅使肾气生肝气，即以水生木，使木
生发。功法是“肘后微扇三”，目标是“以至火起为度”，可见本功
是练精化气，练气生火，使气为少阳壮火，而升发入尾闾，进督脉的一种方法。道家将精出称
做“飞”，飞即外越，高升也。飞金精，即是使肾中金精外越，气化的意义。因本法以微扇肘
而起功，故曰肘后飞金精。
4、金液还丹
真气经三关，至泥丸后，舌舐上 ，就会产生大量口液，咽下时可感到清香味美。道家
认为这是气化之精液，咽下可还归丹田，这就是玉液还丹。如果练到气化精液之后，精气合结，
感到泥丸中有一小丹结成，“其红如桔光似雪，融似汤煎味如蜜”，进入口中可液化，如甘泉般清
爽，蜜糖般甜美，吞入丹田可感到转动，就叫做金液还丹。
黄庭∶黄乃土色，土位中央；庭乃阶前空地。黄庭者，中央空地也。脐内空地，即是黄庭。
《黄庭经》说∶“上有黄庭下关元，后有幽阙前命门”。关元穴在脐下三寸，黄庭之下即是关元
，关元之上即是黄庭，后为幽阙即是脐，名为神阙，前为命门，又名密户，在背脊第十四椎下，黄庭
即这些穴位的中空之处。
丹田，乃结丹之所，如播种生苗结实成丹之田地，故名丹田。
《通玄集》说：补益真气的奥妙道理，关键在于心中没有杂念，内外一切忘却，全部放下，把持住心神。阳气在子时生发，阴气在午时生发，在安静的房间里披衣（或宽衣），双手握固，端正盘膝而坐，收腹下蹲腹部，片刻后起身，胸部前挺而头部微微向后仰。随后打开夹脊双关，手肘在后腰微扇动三次，伸腰使内气自尾闾穴升起，感觉像火一样，从腰部而起，汇聚在夹脊处，千万不要开启关卡，等到此时非常热、真气壮盛时，再依次打开夹脊让气通过。接着仰面脑后，紧紧仰头以封闭上关，千万不要让它打开，就会觉得极热、真气壮盛，再依次进入头顶，以补益泥丸宫和髓海。这样身体就能耐寒暑，这是修习长生的基础。如果像前面那样挺胸、伸腰，闭夹脊存想升气，但腰间之火不起，应当静坐内观，按照方法再做，直到火起为止。从丑时练到寅时，就可以停止。这叫做“肘后飞金精”，又叫做“抽铅使肾气生肝气”。另外稍微昂首仰项放松，让颈下如火烧一般，才点头向前，低头曲项，退舌尖靠近上腭，自然会有津液流出，不漱口直接咽下归还于黄庭，这叫做“金液还丹”。四季不拘时候节次练习此法，从艮卦时辰（丑、寅）到巽卦时辰（辰、巳）为止；晚间则是勒阳关法，从兑卦时辰（酉）到干卦时辰（戌、亥）为止。
解说：《通玄集》说：“补益真气的奥妙道理并非高深莫测，只要放下杂念，使诸事不要挂牵心头，将外界刺激和内心的欲望完全忘却，一齐放在一旁，专心调息，掌握得当，就能收到良好效果。阳气生发于子时（23～1时），阴气生发于午时（11～13时），在阳气和阴气生发的时辰，居于静室，宽衣解带，握固两手，盘膝端坐，下收腹肚，从容伸直身躯，使胸向前挺出而稍仰头于后，采用此姿式，练气日久后便能用气通开夹脊双关。通关时需用肘在后腰微动三次，伸腰使内气自尾闾穴开始入脊中（督脉），其感觉如能似火团那样，自腰而起，拥至夹脊，此时慎勿开关，要等待时机感觉火至甚热，气壮之时，方可根据次开夹脊下关先放气过入脊中。气入脊中后仍仰面脑后，使后脑紧枕脊柱封闭上关，慎勿让开，觉到内气如火，热极之时，方为气壮，根据次再开上关，使气入头顶，以补益泥丸和髓海。这时便可使身体耐寒暑，这种功法是修练长生的基本功。如前姿势，挺胸，伸腰，开夹脊后存内气，而内气升到腰间后不能起火，当静坐内观腰间（丹田）之气，如前法再作，以火起为度。自丑时（1～3时）练功到寅时（3～5时），方可停止。
这种功法叫肘后飞金精，又称抽铅使肾气生肝气。另有一法稍抬头仰项，使颈下如有火起，才点头向前，低头屈项，将舌尖稍向后退舐于上腭，口内自然就会有津液流出，不要漱吐而咽下，使归还于黄庭（胃内）。这种功法叫做金液还丹。此功不受时间节气限制，可四季经常练习，每日自艮（丑、寅）经震（卯）练至巽（辰、巳）（1～11时）退出。晚间练功时又称勒阳关法，自兑（酉）练至干（戌、亥）（18～23时）退出。
小结：
本篇简明地论述了“周天功”的练功方法和要点，着重讲解了“收心”、“通关”、“肘后飞金精”和“金液还丹”的练法。
1、周天功
古人把天体的营运，按方位分为365度，二十八宿。把北斗七星的斗柄沿二十八宿排列的轨道旋转一周，称为一个周天。日月沿此循行一周亦称一周天。人身如同一个小天地，气血环行周身一度也叫一周天。如《灵枢》说：“人身穴道三百六十五穴会，以应周天之数。”气功家把人的真气沿经络循行一周，称为一周天。把使真气循经络而行的功法，叫做周天功。周天功有大周天、小周天、意念周天、丹道周天、经络周天等多种。本篇所述的小周天，即使真气沿督脉上升，再循任脉下降，成一封闭圈。具体的路线和关口是：使丹田真气──伸腰自尾闾穴──入腰脊正中督脉──拥在夹脊关──待气壮后开夹脊关──使真气达上关（玉枕穴）──待气壮后开上关──使真气入头顶（百会穴）以补泥丸和髓海──然后舌舐上腭引口中津液──使真气变成的“金液”咽下还归于黄庭胃内──最后复归入丹田──再由丹田练气进入尾闾关。这样督任两脉便相通，形成了一个周天。在这一周天中真气要通过“三关”、入“泥丸”、“髓海”、变为“金液”，入“黄庭”归还丹田，环循于任督二脉。
何谓“三关”及“夹脊双关”？《寥阳殿问答篇》说：“人之尾闾，在尻脊上第三节，一名长强，一名三岔路，一名河车路，一名禁门。其下曰关元，其前曰气海，乃阴阳变化之乡，任督交会之处，丹书名曰尾闾关者是也。人之背脊二十四节，上应二十四气，在关在二十四节头尾之中，一名双关，直透顶门，此即夹脊关也。人之后脑骨，一名风池，其窍最小而难开，欲开此窍，舌柱上腭，目闭顶门，全仗神炉栗火，接续冲赴，此关乃开，此关名玉枕，又曰铁壁也。”由此可见三关是尾闾关、夹脊关、玉枕关。本文中的“夹脊双关”就是夹脊关，又名双关，上关就是玉枕关，又名铁壁关。该书还对开三关作了详细描述，说：“下田三宝（精气神名曰人身三宝）充盈，乃有无路可走之势，自然冲开尾闾，从太元逆流，隐隐有两股暖气，上肾堂过脊背……但至夹脊者，学人道浅，宝积未富，那能一时便得直透而上，切勿烦躁欲速，惟自日日行之，意中须以心目相送，微用提撮谷道（肛门）法，如辘轳循环，自然志至气次，时候一到，片晌之间，夹脊自开，双关自辟，直上玉枕。玉枕一关，名曰铁壁，居头凹处，有一高骨，尤难过此，必须闭目上视，低头用意，直透此关，上至泥丸，与神交合。此时景象，有如雷轰电掣，火焚波沸，种种形声，似真似幻，切须牢守身心，勿惊勿喜，徐徐自定，清磬冷然入两耳，泥丸、昆仑之间，有如火珠一颗，盘旋不已，隐现于眉间，觉从鼻内而下玄膺，仍自降入气管，乃由华盖，绛宫，直抵丹田。此时身心乐快，难以言喻，所请乾坤交媾罢，一点落黄庭是也。”本文指出为让真气过关，须从体位和使气壮实二方面入手，体位要“端坐盘膝，蹲下腹肚，须曳升身，前出胸而微偃首于后”，“仰面脑后”，“昂首偃项”，这和一般方书主张正坐，身须平直，认为体不端直，则气机塞者不同，独僻一言之家，另有自己见解。对于通过三关，主张务必使气壮实，气不壮则“慎勿开关”或“仰面脑后紧偃以闭上关”，等待“如火相似，自腰而起，拥在夹脊，”“甚热，气壮”或“热极，气壮”，方才根据次开关。如腰间火不起，当静内观丹田，务使火起才开关。
2、收心
就是止念，道家又称炼已。就是要排除各种杂念，使心猿归正，意马收缰，正如《规中指南》所说：“牢擒意马锁心猿，慢着功夫炼汞铅，大道教人先止念，念头不住亦徒然。”收心的第一要诀为“忘记”，就是练习时要“内外俱忘”心头诸事，把它们一齐放在一旁，只有这样才能专心守一。所以《保生秘要》说，“摄心归一，专其一处，皆可止念。”本文将收心列为“补真妙理”是非常有见地的。
3、肘后飞金精
又叫抽铅使肾气生肝气法。《周易参同契》认为：坎为肾，属北方王癸水，色黑，在丹称黑铅或黑虎。所谓抽铅，《悟真篇补注》说：“抽铅添汞，犹云取坎填离，凡进火退符，皆是抽铅。”可见抽铅就是取肾中真水（也即真精，道家谓之金精），以济心火（汞在丹为心，属南方丙丁火），使夫妻交媾，阴阳相济，或取肾水以涵养肝木，使肝气生发。本文讲的是抽铅使肾气生肝气，即以水生木，使木生发。功法是“肘后微扇三”，目标是“以至火起为度”，可见本功是练精化气，练气生火，使气为少阳壮火，而升发入尾闾，进督脉的一种方法。道家将精出叫做“飞”，飞即外越，高升也。飞金精，即是使肾中金精外越，气化的意义。因本法以微扇肘而起功，故曰肘后飞金精。
4、金液还丹
真气经三关，至泥丸后，舌舐上腭，就会产生大量口液，咽下时可感到清香味美。道家认为这是气化之精液，咽下可还归丹田，这就是玉液还丹。如果练到气化精液之后，精气合结，感到泥丸中有一小丹结成，“其红如桔光似雪，融似汤煎味如蜜”，进入口中可液化，如甘泉般清爽，蜜糖般甜美，吞入丹田可感到转动，就叫做金液还丹。
黄庭：黄乃土色，土位中央；庭乃阶前空地。黄庭者，中央空地也。脐内空地，即是黄庭。《黄庭经》说：“上有黄庭下关元，后有幽阙前命门”。关元穴在脐下三寸，黄庭之下即是关元，关元之上即是黄庭，后为幽阙即是脐，名为神阙，前为命门，又名密户，在背脊第十四椎下，黄庭即这些穴位的中空之处。
丹田，乃结丹之所，如播种生苗结实成丹之田地，故名丹田。
The *Tongxuan Ji* (Collection of Profound Mysteries) states: The profound principle of replenishing true qi (vital energy) lies in having no distractions in the mind, forgetting both internal and external stimuli, letting go of everything, and maintaining firm control over the spirit. Yang qi arises at Zi hour (11:00 PM–1:00 AM), and Yin qi arises at Wu hour (11:00 AM–1:00 PM). In a quiet room, with clothes loosened, hold the hands in the "wielding solid" (Wogu, 握固) gesture, sit upright with legs crossed, draw in the abdomen, and after a moment, straighten the body, protruding the chest slightly while tilting the head backward. Subsequently, open the Double Pass of the Jiaji region (Jiaji Shuangguan, 夹脊双关); fan the elbows behind the lower back three times, extend the waist so that internal qi rises from the Weilu acupoint (Tailbone Acupoint), feeling as if fire is rising from the waist and gathering at the Jiaji region. Do not open the pass yet; wait until it feels extremely hot and the qi becomes robust, then gradually open the Jiaji pass to allow the qi to pass through. Then, tilt the head back, pressing the back of the head tightly against the spine to close the Upper Pass (Shangguan, 上关); do not let it open. You will feel extreme heat and robust qi, then gradually allow the qi to enter the top of the head to nourish the Niwan Palace (Mud Pill Palace, 泥丸宫) and the Marrow Sea (Suihai, 髓海). This enables the body to withstand cold and heat and serves as the foundation for cultivating longevity. If, after protruding the chest and extending the waist to close the Jiaji pass and visualize the ascending qi, the fire does not rise in the waist, sit quietly and observe internally; repeat the method until the fire rises. Practice from Chou hour (1:00–3:00 AM) to Yin hour (3:00–5:00 AM), then stop. This is called "Flying Golden Essence from Behind the Elbow" (Zhouhou Fei Jinjing, 肘后飞金精), also known as "Extracting Lead to Make Kidney Qi Generate Liver Qi" (Chou Qian Shi Shenqi Sheng Ganqi, 抽铅使肾气生肝气). Alternatively, slightly raise the head and neck, allowing a sensation of fire under the neck; then nod forward, bow the head and curve the neck, retract the tip of the tongue toward the upper palate (Shangying, 上腭). Saliva will naturally flow out; swallow it without rinsing and return it to the Huangting (Yellow Court, 黄庭). This is called "Golden Liquid Returning to the Elixir" (Jinye Huan Dan, 金液还丹). This practice can be performed at any time during the four seasons, from Gen hours (Chou, Yin) to Xun hours (Chen, Si); in the evening, it is the method of "Restraining the Yang Pass" (Le Yangguan, 勒阳关), from Dui hours (You) to Qian hours (Xu, Hai).
Commentary: The *Tongxuan Ji* says: "The profound principle of replenishing true qi is not obscure; simply let go of distracting thoughts, do not let affairs burden the mind, completely forget external stimuli and inner desires, set them aside, focus on regulating breath, and maintain proper control to achieve good results. Yang qi arises at Zi hour (11:00 PM–1:00 AM), and Yin qi arises at Wu hour (11:00 AM–1:00 PM). During these hours, reside in a quiet room, loosen clothing, hold the hands in Wogu, sit upright with legs crossed, draw in the abdomen, and calmly straighten the body, protruding the chest and tilting the head slightly backward. With this posture, after long-term practice, one can use qi to open the Double Pass of the Jiaji region. To open the pass, move the elbows behind the lower back three times, extend the waist so internal qi enters the Du Meridian (Governing Vessel) starting from the Weilu acupoint. The sensation is like a ball of fire rising from the waist and gathering at Jiaji. At this point, do not open the pass; wait for the timing when the heat is intense and the qi is robust, then gradually open the lower Jiaji pass to release the qi into the spine. After the qi enters the spine, tilt the head back, pressing the back of the head tightly against the spine to close the Upper Pass; do not let it open. When the internal qi feels like fire and reaches extreme heat, indicating robust qi, gradually open the Upper Pass to allow the qi to enter the top of the head, nourishing the Niwan Palace and Marrow Sea. This allows the body to resist cold and heat; this method is the basic skill for cultivating longevity. If, after protruding the chest, extending the waist, opening the Jiaji pass, and visualizing the internal qi, the qi rises to the waist but fails to generate fire, sit quietly and observe the qi in the waist (Dantian); repeat the previous method until the fire rises. Practice from Chou hour (1:00–3:00 AM) to Yin hour (3:00–5:00 AM), then stop.
This method is called 'Flying Golden Essence from Behind the Elbow,' also known as 'Extracting Lead to Make Kidney Qi Generate Liver Qi.' Another method involves slightly raising the head and neck, creating a sensation of fire under the neck; then nod forward, bow the head and curve the neck, retract the tongue tip to touch the upper palate. Saliva will naturally flow; swallow it without spitting and return it to the Huangting (Stomach area). This method is called 'Golden Liquid Returning to the Elixir.' This practice is not restricted by seasons or solar terms and can be practiced regularly throughout the year, daily from Gen hours (Chou, Yin) through Zhen hours (Mao) to Xun hours (Chen, Si) (1:00 AM–11:00 AM). Evening practice is called the 'Restraining the Yang Pass' method, from Dui hours (You) to Qian hours (Xu, Hai) (6:00 PM–11:00 PM).
Summary:
This section briefly discusses the methods and key points of practicing 'Zhou Tian Gong' (Microcosmic Orbit Exercise), focusing on 'Collecting the Mind' (Shouxin, 收心), 'Opening the Passes' (Tongguan, 通关), 'Flying Golden Essence from Behind the Elbow' (Zhouhou Fei Jinjing, 肘后飞金精), and 'Golden Liquid Returning to the Elixir' (Jinye Huan Dan, 金液还丹).
1. Zhou Tian Gong (Microcosmic Orbit Exercise)
Ancients divided celestial movements into 365 degrees and twenty-eight mansions. One complete rotation of the Big Dipper's handle along the orbit of the twenty-eight mansions is called one Zhou Tian (Celestial Circuit). The sun and moon completing one circuit along this path is also called one Zhou Tian. The human body is like a small heaven and earth; one circulation of qi and blood around the body is also called one Zhou Tian. As stated in the *Lingshu* (Spiritual Pivot): "The human body has 365 acupoints, corresponding to the number of degrees in the Zhou Tian." Qigong masters refer to the circulation of true qi along the meridians as one Zhou Tian. The method that causes true qi to circulate along the meridians is called Zhou Tian Gong. There are many types, such as Large Zhou Tian, Small Zhou Tian, Intentional Zhou Tian, Daoist Alchemy Zhou Tian, and Meridian Zhou Tian. The Small Zhou Tian described here refers to true qi rising along the Du Meridian (Governing Vessel) and descending along the Ren Meridian (Conception Vessel), forming a closed loop. The specific route and passes are: True qi from the Dantian (Elixir Field) → extend waist from Weilu acupoint → enter the center of the lumbar spine (Du Meridian) → gather at the Jiaji Pass → wait for robust qi to open the Jiaji Pass → true qi reaches the Upper Pass (Yuzhen Acupoint) → wait for robust qi to open the Upper Pass → true qi enters the top of the head (Baihui Acupoint) to nourish Niwan Palace and Marrow Sea → tongue touches upper palate to guide saliva → swallow the 'golden liquid' formed by true qi back to the Huangting (Stomach) → finally return to the Dantian → cultivate qi from the Dantian entering the Weilu Pass again. Thus, the Du and Ren meridians connect, forming a Zhou Tian. In this cycle, true qi passes through the 'Three Passes,' enters the 'Niwan Palace' and 'Marrow Sea,' transforms into 'Golden Liquid,' enters the 'Huangting,' returns to the Dantian, and circulates along the Du and Ren meridians.
What are the 'Three Passes' and 'Double Pass of Jiaji'? The *Liaoyangdian Wen Da Pian* (Q&A Chapter of Liaoyang Hall) states: "The Weilu of humans is the third vertebra above the sacrum, also named Changqiang, San Cha Lu, He Che Lu, and Jin Men. Below it is Guanyuan, in front is Qihai, the place of yin-yang transformation and the intersection of Ren and Du meridians; Daoist alchemy books call this the Weilu Pass. Humans have 24 spinal vertebrae, corresponding to the 24 solar terms. Between the heads and tails of these 24 vertebrae is a place called Double Pass, penetrating straight to the crown; this is the Jiaji Pass. The bone at the back of the head is named Fengchi; its aperture is small and difficult to open. To open this aperture, press the tongue to the upper palate, close the eyes and focus on the crown, relying entirely on the栗火 (chestnut fire) of the divine furnace to continuously rush forward; only then will this pass open. This pass is named Yuzhen, also called Tiebi (Iron Wall)." From this, we see the Three Passes are the Weilu Pass, Jiaji Pass, and Yuzhen Pass. The 'Double Pass of Jiaji' in this text is the Jiaji Pass, also known as Double Pass; the Upper Pass is the Yuzhen Pass, also called Tiebi Pass. The book describes opening the three passes in detail: "When the Three Treasures of the Lower Field (Essence, Qi, Spirit) are full, there is nowhere else to go, naturally bursting open the Weilu, flowing counter-current from Taiyuan, with two streams of warm air rising past the kidney hall and over the back... But reaching Jiaji, those with shallow Daoist paths and insufficient accumulation cannot penetrate straight up immediately. Do not be impatient or seek quick results; practice daily, sending the intention with mind and eyes, slightly using the method of lifting the Gu Dao (anus), like a water wheel rotating. Naturally, when the time comes, within a short while, the Jiaji will open, the Double Pass will clear, going straight to Yuzhen. The Yuzhen Pass, named Tiebi, is located in the depression of the head, with a high bone, especially difficult to cross. One must close the eyes and look up, bow the head and concentrate intent, penetrating straight through this pass to reach Niwan, where spirit and essence combine. The scene at this time is like thunder and lightning, fire burning and waves boiling, various forms and sounds, seeming real yet illusory. One must firmly guard body and mind, not startled nor pleased, slowly settling down. Clear bell sounds enter the ears coolly; between Niwan and Kunlun, a fire-like pearl spins endlessly, appearing and disappearing between the eyebrows, feeling as if it descends from the nose through Xuan Ying, down the trachea, through Huagai and Jianggong, straight to the Dantian. At this time, body and mind are joyful beyond words; this is what is meant by 'after the union of Heaven and Earth, a single point falls into the Huangting.'" This text points out that to help true qi pass through the passes, one must start from body posture and strengthening the qi. Posture should be "sit upright with legs crossed, draw in the abdomen, straighten the body, protrude the chest and tilt the head slightly backward," "tilt face and back of head," "raise head and arch neck." This differs from general manuals advocating sitting upright with a straight body, believing that an unstraight body blocks qi mechanism; this unique school has its own views. Regarding passing the three passes, it emphasizes ensuring the qi is robust; if the qi is not robust, "do not open the pass" or "press the back of the head tightly against the neck to close the Upper Pass," waiting for sensations like "fire rising from the waist, gathering at Jiaji," "extremely hot, robust qi," or "extreme heat, robust qi," before gradually opening the pass. If fire does not rise in the waist, observe the Dantian internally until the fire rises before opening the pass.
2. Collecting the Mind (Shouxin)
This means stopping thoughts, also known in Daoism as Lian Yi (Refining the Self). It requires eliminating all distracting thoughts, bringing the 'mind monkey' to order and reinning in the 'willful horse.' As the *Guizhong Zhinan* (Guide to the Center) says: "Firmly capture the willful horse and lock the mind monkey; slowly apply effort to refine mercury and lead. The Great Way teaches people to first stop thoughts; if thoughts do not cease, it is futile." The first key to collecting the mind is 'forgetting'; during practice, one must "forget both internal and external" matters on the mind, setting them aside, so as to focus exclusively on one thing. Thus, the *Baosheng Miyao* (Secret Essentials of Preserving Life) says, "Gathering the mind into one, specializing in one place, can all stop thoughts." Placing 'collecting the mind' as the 'profound principle of replenishing true' is very insightful.
3. Flying Golden Essence from Behind the Elbow (Zhouhou Fei Jinjing)
Also called the method of extracting lead to make kidney qi generate liver qi. The *Zhouyi Cantong Qi* (Kinship of the Three) considers Kan as the Kidney, belonging to Northern Gui Water, black color, called Black Lead or Black Tiger in alchemy. Extracting Lead, according to the *Wuzhen Pian Buzhu* (Supplement to the Verse of Awakening to Reality), says: "Extracting lead and adding mercury is like taking Kan to fill Li; all advancing fire and retreating talisman practices are extracting lead." Thus, extracting lead means taking the true water (true essence, called Golden Essence in Daoism) from the Kidney to balance Heart Fire (Mercury represents the Heart, belonging to Southern Bing Ding Fire), causing husband and wife to mate, yin and yang to complement each other, or taking Kidney water to nourish Liver Wood, causing Liver Qi to arise. This text discusses extracting lead to make kidney qi generate liver qi, i.e., using water to generate wood, causing wood to arise. The method is "fan the elbows behind three times," with the goal being "until the fire rises." Thus, this practice refines essence into qi, qi into fire, making the qi a vigorous Shaoyang fire, rising into the Weilu and entering the Du Meridian. Daoists call the emergence of essence 'Fei' (Flying), meaning outward expansion and rising. Flying Golden Essence means the golden essence in the Kidney expands outward, signifying qi transformation. Because this method starts by fanning the elbow, it is called 'Flying Golden Essence from Behind the Elbow.'
4. Golden Liquid Returning to the Elixir (Jinye Huan Dan)
After true qi passes through the three passes and reaches the Niwan Palace, touching the tongue to the upper palate produces abundant saliva, which tastes clear and fragrant when swallowed. Daoists believe this is qi-transformed essence fluid; swallowing it returns it to the Dantian, which is Jade Liquid Returning to the Elixir (Yuye Huan Dan). If practice continues until after qi-transformed essence fluid, essence and qi combine, and a small elixir forms in the Niwan, "red like orange light, white like snow, melting like boiled soup, tasting like honey," liquefying in the mouth, refreshing like spring water, sweet like honey, and rotating in the Dantian upon swallowing, it is called Golden Liquid Returning to the Elixir.
Huangting (Yellow Court): Huang is the color of earth, earth is in the center; Ting is the empty space before the steps. Huangting is the central empty space. The empty space inside the navel is the Huangting. The *Huangting Jing* (Yellow Court Classic) says: "Above is Huangting, below is Guanyuan; behind is Youque, in front is Mingmen." The Guanyuan acupoint is three cun below the navel; below Huangting is Guanyuan, above Guanyuan is Huangting. Behind is Youque, which is the navel, named Shenque; in front is Mingmen, also named Mi Hu, below the 14th thoracic vertebra on the back. Huangting is the hollow space among these acupoints.
Dantian (Elixir Field) is the place where the elixir forms, like a field where seeds are sown, sprout, and bear fruit as an elixir, hence the name Dantian.