The *Qianjin Fang* (Essential Prescriptions Worth a Thousand Gold) discusses: When a newborn is first born, one should first wrap a finger with cotton wool and wipe the blueish mud and foul blood from the infant's mouth and tongue. This is called "Yu Heng" (Jade Balance) (also known as "Xian"). If not wiped promptly, once the infant cries, these impurities will enter the abdomen and cause various diseases. The *Qianjin Yi Fang* (Supplement to Essential Prescriptions Worth a Thousand Gold) states: It leads to the formation of masses (*Pi*) and death.

The *Taiping Shenghui Fang* (Holy惠民 Formulas of the Taiping Era) discusses: After an infant takes its first feed, wrap a finger with hair, dip it in clear water, and wipe clean. Observe if there are two yellow tendons at the gum line; if so, cut them with a reed knife and apply pig milk to cure it. If the infant's mouth is difficult to open, simply applying pig milk first will cause it to open naturally.

The *Xiao'er Jiyan Fang* (Experienced Formulas for Children) states: For a newborn, every day use the first bucket well water or slightly warm water. Wrap a clean, soft old cloth around the lactating mother's finger, dip it in water, and wipe the infant's mouth. Gently press the tongue and both cheeks to make them slightly loose and comfortable. This prevents diseases such as trismus (lockjaw), accumulated heat, and wind disorders. People in the capital region and Shandong often practice this, calling it "Na Er Kou" (Pressing the Infant's Mouth). After wiping, apply a small amount of finely ground dry坯 cinnabar mixed with musk to the infant's mouth to beautify the breasts and promote feeding.

The *Xiao'er Jiyan Fang* also says: In Dongping, there was an old woman skilled at wiping infants' mouths to prevent "Lian Yin" (a specific lip disorder). She said: At the junction where the upper and lower lips connect to the teeth, there is a tendon pulling. If the tendon on the upper lip is tight, "Shang Lian" (Upper Lian) occurs; if the tendon on the lower lip is tight, "Xia Lian" (Lower Lian) occurs. Shang Lian manifests as sores all over the head or between the eyebrows, resembling tinea (ringworm). It causes incessant itching and occasionally oozes yellow fluid, which generates new sores where it flows. Xia Lian starts on the waist and back, gradually spreading to the limbs, also resembling tinea, with incessant itching and yellow discharge. If the disease is severe and untreated, or if the head and face become connected, it may persist for years without improvement. Further biting may lead to major illnesses. The method is to take a cup of warm water every morning, have the lactating mother wrap her index finger with an old, soft, clean cloth, dip it in warm water to wipe the infant's mouth, and rinse the water down. Wipe and press simultaneously to keep the mouth clean and relax the tendons above and below. Then the infant will feed well naturally, and various diseases will not arise. It is also said: There will never be Lian Yin as long as the tendons are relaxed. In the capital, one can see countless cases where infants, due to lack of pressing care, develop trismus and refuse milk, or develop Lian Yin because the pressing technique was not understood.