《太上玄真诀》服日月法∶东卿司命君曰∶先师王君，昔见授太上明堂玄真上经，清斋休粮，
存日月在口中，昼存日，夜存月，令大如环，日赤色，有紫光九芒，月黄色，有白光十芒，存咽，
服光芒之液，常密行之无数。若不修存时，日月住面明堂中，日居左，月居右，二景与日童气合
通也。此道所以摄运生精，理鬼神，六丁奉侍，天兵卫护。此上真道也，大都口诀止如此。
服日月之精华者，欲得常食竹笋者，日华之胎也，一名大明。又欲常食鸟脯者，月胎之羽鸟
也，一名月鹭。欲服日月，当食此物，气感运之。太虚真人曰∶鸿者，羽族之总名也。其鹄雁鹅
鸥，皆曰鸿鹭也。
服日气法∶以平旦采日华，以夜半存之，去面前九寸，令万景照我泥丸，下及五脏，洞彻一
形，引气入口，光色蔚明，良久乃毕，则常得长生矣。
又法，夜半生气时，若鸡鸣时，正卧闭目。从左目中出日，右目中出月，并径九寸，在两耳
之上。两耳之上，名为六合高窗也。令日月使照一身，内彻泥丸，下照五脏。肠胃之中，皆觉见
了，洞彻内外，令一身与日月光合，良久毕，叩齿九通，咽液九过，乃微祝曰∶太山玄一，九皇
吐精。三五七遍，洞观幽冥。日月垂光，下彻神庭。使照六合，太乙黄宁。帝君命简，金书不倾。
五老奉符，天地试同。使我不死，以致真灵。却过万邪，祸害灭中。上朝天皇，返老还婴。太上
有制，百神敬听。毕，乃开明，为日月练根三元技魂，以制御用神，辟诸鬼气之来侵，使长生不
死，多存之矣。
又法∶又存左目为日，右目为月，共合神夜之中，却上入于明堂，死生黄英之体，下流口中，
九咽以哺太乙，常以生气时存之，毕，微祝曰∶日月上精，黄水月华。太乙来饮，神光高罗。使
我长生，天地同柯。五日以行之，口中舌上为神庭，存日月既毕，因动舌，觉有黄泉如紫金色，
从舌上出流，却入明堂，为黄英之醴也。存思之时，常闭目施念。
《太上玄真诀》中关于服食日月精华的方法：东卿司命君说：先师王君，过去曾传授给我《太上明堂玄真上经》，要求清心斋戒、停止进食谷物，存想日月位于口中。白天存想太阳，夜晚存想月亮，使其大小如环状。太阳呈赤色，带有九道紫色光芒；月亮呈黄色，带有十道白色光芒。通过存想将其咽下，服食其光芒所化的津液，经常秘密修持，数量不限。如果不进行存想时，日月便停留在面部的明堂穴中，太阳在左，月亮在右，两景与日童之气相通。此道可以摄取运化生命精气，调理鬼神关系，有六丁神奉侍，天兵护卫。这是上真之道，大致的口诀就是这些。
想要服食日月的精华，应当经常食用竹笋，因为竹笋是太阳之气的胚胎，又名“大明”。又应当经常食用鸟肉干，因为那是月亮之气的胚胎——羽类鸟类，又名“月鹭”。想要服食日月，就应当食用这些食物，通过气息感应来运化它们。太虚真人说：“鸿”是羽族鸟类的总称。其中的鹄、雁、鹅、鸥，都称为鸿鹭。
服食日气的方法：在清晨平旦时分采集日华之气，到夜半时分进行存想。距离面前九寸处，让万道光芒照射我的泥丸宫，向下遍及五脏，透彻全身，引导气进入口中，光色鲜明灿烂，持续很久才结束，这样就能常得长生。
另一种方法：在夜半阳气生发之时，或者鸡鸣时分，端正躺卧并闭上眼睛。从左眼中生出太阳，从右眼中生出月亮，直径均为九寸，位于双耳之上。双耳之上的位置，被称为“六合高窗”。让日月之光照射全身，向内通达泥丸宫，向下照耀五脏。肠胃之中，都能觉察看见，洞彻内外，使全身与日月光融合，持续很久结束后，叩齿九次，吞咽津液九次，然后低声祝祷说：“太山玄一，九皇吐精。三五七遍，洞观幽冥。日月垂光，下彻神庭。使照六合，太乙黄宁。帝君命简，金书不倾。五老奉符，天地试同。使我不死，以致真灵。却过万邪，祸害灭中。上朝天皇，返老还婴。太上有制，百神敬听。”完毕后，睁开眼，通过日月修炼根本和三元之魂，以控制运用元神，辟除各种鬼气来侵扰，从而长生不死，应多进行这种存想。
又一种方法：存想左眼为太阳，右眼为月亮，共同合于神夜之中，然后向上进入明堂穴，形成死生黄英之体，向下流入口中，分九次咽下以哺育太乙，经常在阳气生发时进行存想。完成后，低声祝祷说：“日月上精，黄水月华。太乙来饮，神光高罗。使我长生，天地同柯。”连续五日施行这种方法。口中舌上部位为神庭，存想日月结束后，随即动舌，感觉有黄泉般的液体如紫金色，从舌上流出，回流至明堂，成为黄英之甘醴。在存思的时候，经常闭目施念。
The method of consuming the essence of the sun and moon from *Taishang Xuanzhen Jue*: The Lord Dongqing Siming said: My former master, Wang Jun, previously transmitted to me the *Taishang Mingtang Xuanzhen Shangjing*, requiring pure fasting (Qingzhai) and grain avoidance (Xiuliang), visualizing the sun and moon within the mouth. During the day, visualize the sun; at night, visualize the moon, making them as large as a ring. The sun is red with nine purple rays; the moon is yellow with ten white rays. By visualization, swallow them, consuming the fluid transformed from their radiant light, practicing secretly and frequently without limit. When not practicing visualization, the sun and moon reside in the Mingtang acupoint on the face, with the sun on the left and the moon on the right, allowing the two scenes to connect with the Qi of the Sun Child. This Dao allows for the collection and operation of vital essence, regulating spirits and ghosts, attended by the Six Ding deities and guarded by heavenly soldiers. This is the Way of the Highest Truths; the general mantras are essentially as follows.
Those who wish to consume the essence of the sun and moon should frequently eat bamboo shoots, as they are the embryo of the sun's Qi, also known as "Da Ming." They should also frequently eat dried bird meat, as it is the embryo of the moon's Qi—birds of the feather class, also known as "Yuelu." To consume the sun and moon, one should eat these substances, utilizing Qi resonance to transform them. The True Person Taixu said: "Hong" is the general name for birds of the feather class. Among them, hu, yan, e, and ou are all called Honglu.
Method of consuming solar Qi: Collect the solar brilliance at dawn (Pingdan), and practice visualization at midnight. Position it nine cun in front of the face, allowing myriad rays to illuminate your Niwan Palace, extending down to the five zang organs, penetrating the entire body. Guide the Qi into the mouth, where the light color becomes bright and splendid. Continue for a long time until completion, thereby attaining longevity.
Another method: At the time when Yang Qi begins to generate at midnight, or during the rooster's crow, lie straight with eyes closed. Generate the sun from the left eye and the moon from the right eye, each with a diameter of nine cun, positioned above both ears. The area above both ears is named the "High Window of the Six Directions." Let the light of the sun and moon shine upon the whole body, penetrating inward to the Niwan Palace and shining downward on the five zang organs. Within the intestines and stomach, everything can be perceived clearly, penetrating inside and out, merging the whole body with the light of the sun and moon. After continuing for a long time, click the teeth nine times and swallow saliva nine times, then silently chant: "Taishan Xuanyi, Jiuhuang spits essence. Three-five-seven cycles, penetrate the dark underworld. Sun and moon hang down light, reaching Shenming below. Illuminating the six directions, Taiyi brings peace. The Emperor's decree scroll, golden writing does not tilt. Five Elders present the talisman, heaven and earth test as one. Make me immortal, reaching true spirit. Repel ten thousand evils, disasters extinguished in the midst. Ascend to see the Heavenly Emperor, return to youth like an infant. The Supreme has decreed, hundred gods listen respectfully." Upon completion, open the eyes, refining the root and the souls of the Three Primordials through the sun and moon, to control and utilize the divine spirit, repelling invading ghostly Qi, thus achieving immortality. One should practice this visualization often.
Yet another method: Visualize the left eye as the sun and the right eye as the moon, combining in the divine night, then ascending into the Mingtang acupoint, forming the body of Huangying of life and death, flowing downward into the mouth, swallowing nine times to nourish Taiyi. Practice this visualization frequently during times when Yang Qi generates. Upon completion, silently chant: "Essence of the sun and moon above, yellow water and moon brilliance. Taiyi comes to drink, divine light hangs high. Make me live forever, sharing branches with heaven and earth." Practice this method for five consecutive days. The tongue and palate in the mouth constitute Shenming. After finishing the visualization of the sun and moon, move the tongue, feeling a spring-like liquid resembling purple-gold flow from the tongue, returning to the Mingtang, becoming the sweet nectar of Huangying. During visualization, keep the eyes closed and maintain the mental intention.