（别录上品）
【气味】甘，微寒，无毒。
【主治】主补五脏，利大小肠，治口疮。
【核】曰∶酥出外国，虏名马思哥者是也。随地亦可为，其法用牛乳生汁一斗，入砂
锅内，煎五七沸，滤去滓，倾磁盆内，次早汁面有凝衣，遂撇取之，熬去水气，酥成矣。
宜腊月造，他时者色味易变。有用马、羊乳造者，功用有别，不可不辨也。
先人云∶乳分五味，从乳生酪，从酪生酥。钻摇取者曰生酥，经火取者曰熟酥。酥中之
精曰醍醐，乳一斤，可得酥一两；酥十斤，可得醍醐一两。得醍醐，则酪不可食；得酥，则
酪不可食。谓精粹已出，余皆渣魄耳。
【 】曰∶牛，土畜也。土缓而和，故易坤为牛。牛，胃也，地虽冻，能胃而生也。诗
云∶尔牛来斯，其耳湿湿。湿湿，言润泽也。盖牛之为物，病则耳燥，安则温润而泽，故古
之视牛者以耳。乳者，胃府之别汁，水食之精粹。乳而酪，酪而酥，酥又乳酪之纯粹精也。
故可待腑脏之决而躁，形气之瘁而 。经云∶腑脏形气，皆禀气于胃。胃者，腑脏形气之本
也
若客热咳逆，以及诸疾，咸从燥生，其耳湿湿，力能温润而泽也。坤，阴物也。牛故蹄
拆，病阴，则阳胜，故牛病则立，足太阴病有强立一条，宜为对证，顺其性耳。牛，阴物也。
故起先后足，卧先前足。又不独治强立，并可治四肢拘挛，膝痛不可屈伸矣。顾草本之 ，
尚假牛膝为名，功力较之牛酥，若合符节，比量推度，则得之矣。
（牛尝卧，牛病则立；马尝立，马病则卧。是以牛走喜风顺，马走喜风逆，则凡形骸气
血，经脉支络，逆流而上，与不得顺流而下者，当百倍其力。）
[Recorded in the Superior Category of the Bie Lu]
【Flavor and Nature】Sweet, slightly cold, non-toxic.
【Indications】Primarily tonifies the five Zang organs, unblocks the large and small intestines, and treats mouth ulcers.
【Analysis】It is stated that Su (Clarified Butter/Ghee) originates from foreign lands, where the Hu people call it "Masige" (a transliteration for ghee). It can also be produced locally. The method involves taking one dou (a unit of volume) of fresh cow's milk, boiling it five to seven times in a clay pot, filtering out the dregs, and pouring it into a porcelain basin. Early the next morning, a solidified skin forms on the surface of the liquid; this is skimmed off, boiled to remove moisture, and the Su is formed. It is best prepared in the twelfth lunar month; Su made at other times tends to change in color and flavor. Some use horse or sheep milk to produce it, but its efficacy differs, so this distinction must not be overlooked.
My late father once said: Milk transforms through five flavors/stages; from milk comes Lao (Yogurt/Curd), and from Lao comes Su. What is extracted by churning/shaking is called Sheng Su (Raw Ghee), while what is extracted by heating is called Shu Su (Cooked Ghee). The essence within Su is called Ti Hu (Ghee Essence/Amrita). From one jin (approx. 500g) of milk, one liang (approx. 37.5g) of Su can be obtained; from ten jin of Su, one liang of Ti Hu can be obtained. Once Ti Hu is obtained, the remaining Lao cannot be consumed; once Su is obtained, the remaining Lao cannot be consumed either. This is because the essence has been extracted, leaving only dregs and residue.
【Commentary】It is stated that the ox is an animal associated with Earth. Earth is gentle and harmonious, hence the Kun hexagram in the I Ching symbolizes the ox. The ox corresponds to the Stomach organ; although the earth may be frozen, the ox survives through its Stomach Qi. The Book of Songs states: "Your ox comes here, its ears wet and glossy." "Wet and glossy" describes a moist and lustrous appearance. Generally, when an ox is ill, its ears become dry; when at ease, they are warm, moist, and lustrous. Therefore, ancients observed oxen by looking at their ears. Milk is a special secretion of the Stomach Fu organ, representing the purest essence of water and food. Milk transforms into Lao, Lao transforms into Su, and Su is the purest essence of both milk and Lao. Thus, it can be used to address conditions arising from the rupture and agitation of Zang-Fu functions, as well as the exhaustion of form and Qi. The Classic states: The Qi of the Zang-Fu organs and the form derives from the Stomach. The Stomach is the root of the Zang-Fu organs and the form.
If there is cough and rebellious Qi caused by external heat, or various other diseases, all arise from dryness. The moist and lustrous nature of the ox's ears has the power to moisten and nourish. Kun represents Yin substances. Because the ox is associated with Yin, its hooves may crack; if afflicted by Yin disease, Yang becomes excessive, causing the ox to stand when ill. There is a condition in the Foot Taiyin channel called "rigid standing," which should correspond to this indication, following its natural tendency. The ox is a Yin substance. Therefore, when rising, it lifts its hind legs first; when lying down, it lowers its front legs first. Not only does it treat rigid standing, but it can also treat spasm and contraction of the four limbs, and knee pain with inability to flex or extend. Examining the herb Niuxi (Achyranthes Root), which borrows its name from the ox's knee, its efficacy compared to Niu Su (Ox Ghee) matches perfectly like a tally token. Through comparative reasoning, this understanding is achieved.
(The ox usually lies down but stands when ill; the horse usually stands but lies down when ill. Therefore, oxes prefer walking with the wind, while horses prefer walking against the wind. Thus, for any conditions where the physical body, Qi, blood, meridians, and collaterals flow counter-current upward, or fail to flow downward smoothly, the therapeutic effort should be doubled.)