古仙佛所炼之丹，人皆谓为元精，纯阳菩提，舍利子等物。不知此乃仙佛所炼后天金丹，非先天
元丹。先天元丹者，畀之降衷，禀之父母，无影无形，无声无臭，极诚极明，至虚至灵。不炼后天金丹以辅
之，则渐失于昏，渐至于无。故藉后天以补先天，即以先天统属后天。若第以精气所结为元丹，亦无灵有象
之顽物耳！安能出入由己，生死如归哉？是必炼谷化精，炼精化气，炼气化神，结成金丹，以善养元丹，
于活泼泼地静待天命，安能脱化？斯古仙佛上乘功夫。
养婴之法，修养与胎养不同。胎养之婴，精成形而神具焉。修养之婴，神入定而气送焉，胎养之婴，
藉气以聚神，以活。修养之婴，藉精以蓄气，以导。胎养者，由气生精，由精生神。修养者，以气敛神，
以神调精。胎养之婴成有神，御气以送精，所以先出者为精，是因先天而有后天也。修养之婴，以气
炼精而存神，所中主者为神，是以后天而补先天也。常人不知护蓄、成人后精必亏，气必馁。归时，精
顽气落，神与具散，而入于鬼。修士善于保重，成功后精必凝，气必结。归时，精完气升，神随之出而
存其灵。礼记所谓，魂气升于天，形魄归于地。中庸所谓弗见弗闻，体物不遗者，皆此意也。婴何由
能出？其体至轻，其用至灵，以气之至轻，送神之至灵，自与轻清上浮之天契合。无闲安能不出入上
清乎？要之，婴之能出，必由定之能入，定之能入，必由运之能久，婴由昏而明，明而清，清而轻，轻
而虚，虚而灵，灵而神。斯与天地合撰，日月合明，四时合序，鬼神合吉凶矣。尽人合天，舍此何从。
其理精粹，其事平庸，人习焉不察，遂忽焉不觉耳！慎毋惑于旁门左道，从身中有形之精为婴也。有形
之精，在身中是一块血肉，非轻清之品，如何能到上清世界？！世俗所称肉身成圣，是以肉身修成圣人。
拔宅飞升，是合一宅而飞空上升耳。岂身与宅可安置于上界哉？！纵世有传说！皆后人附合之词也。
揆之于理，万难取信。
古时仙佛所修炼的丹，人们都认为是元精、纯阳菩提、舍利子等物体。却不知道这是仙佛所修炼的后天金丹，并非先天元丹。先天元丹，是上天赋予的本性，禀受于父母，无影无形，无声无臭，极其真诚极其光明，达到极致的虚空与灵动。如果不修炼后天金丹来辅助它，就会逐渐变得昏昧，最终归于虚无。所以借助后天来补益先天，同时以先天统领后天。如果仅仅把精气凝结之物当作元丹，那也只是没有灵性、有具体形象的顽劣之物罢了！怎么能做到随心所欲地出入，视生死如归途呢？这必须通过炼谷化精、炼精化气、炼气化神，结成金丹，以此来善于养护先天元丹，在生机勃勃的状态下静待天命降临，这样才能实现脱胎换骨。这就是古时仙佛的高深功夫。
修养婴儿的方法，与胎养不同。胎养中的婴儿，是精气形成形体而神识具备。修养中的婴儿，是神识进入定境而气息随之引导。胎养的婴儿，借助气息来凝聚神识，使其活跃；修养的婴儿，借助精气来蓄积气息，以此导引。胎养的过程，是由气生精，由精生神；修养的过程，是以气收敛神识，以神识调节精气。胎养的婴儿成形后具有神识，驾驭气息来送精，所以先出来的是精，这是因为先天而生出后天。修养的婴儿，用气息炼化精气而存留神识，其中起主导作用的是神识，这是以后天来补益先天。普通人不知道保护和蓄养，成年后精气必然亏损，气息必然萎靡。死亡时，精气顽固僵滞，气息坠落，神识与形体一同消散，从而沦为鬼魂。修道之人善于保重身体，成功后精气必然凝练，气息必然结聚。死亡时，精气完备，气息上升，神识随之而出并保留其灵性。《礼记》所说的，魂气升于天，形魄归于地；《中庸》所说的，看不见听不到，但体现在万物中无所遗漏的道理，都是这个意思。婴儿怎么能出去呢？它的本体极其轻盈，它的作用极其灵动，凭借气息的至轻，送别神识的至灵，自然与轻清上浮的天界相契合。如果没有闲暇（指杂念干扰），怎么能不出去进入上清境界呢？总之，婴儿能够出去，必定是因为定力能够深入；定力能够深入，必定是因为运功能够持久。婴儿从昏沉到清明，从清明到清澈，从清澈到轻盈，从轻盈到虚空，从虚空到灵动，从灵动到通神。这样就能与天地合撰，与日月合明，与四时合序，与鬼神合吉凶了。尽人合天，除了这个方法还有什么途径呢？其中的道理精粹，事情看似平庸，人们习以为常而不察觉，于是忽略不觉醒罢了！千万不要被旁门左道迷惑，把身体中有形的精液当作婴儿。有形的精液，在身体里只是一块血肉，不是轻清的品类，怎么能到达上清世界呢？世俗所称的肉身成圣，是指以肉身修成圣人。拔宅飞升，是指连同整个宅院一起飞空上升。难道身体和宅院可以安置在上界吗？即使世间有传说，也都是后人附会的言辞。推究其理，万难取信。
The elixir refined by ancient immortals and Buddhas is generally considered by people to be Yuanjing (Primordial Essence), Pure Yang Bodhi, Sarira (Relic), and other substances. However, they do not realize that this is the Postnatal Golden Elixir refined by immortals and Buddhas, not the Prenatal Primordial Elixir. The Prenatal Primordial Elixir is endowed by Heaven, inherited from parents, without shadow or form, without sound or smell, extremely sincere and bright, reaching the utmost emptiness and spirituality. If one does not refine the Postnatal Golden Elixir to assist it, one will gradually become dim and eventually vanish into nothingness. Therefore, one uses the Postnatal to supplement the Prenatal, while simultaneously using the Prenatal to govern the Postnatal. If one merely regards the congealed essence and qi as the Primordial Elixir, it is but a dull object with spiritlessness and tangible form! How could it be able to enter and exit at will, regarding life and death as returning home? One must refine grain into essence, refine essence into qi, refine qi into spirit, and condense them into a Golden Elixir, thereby properly nurturing the Primordial Elixir. Only by waiting quietly for the Mandate of Heaven in a vibrant state can one achieve transformation. This is the supreme skill of ancient immortals and Buddhas.
The method of nourishing the infant differs from fetal nourishment. In fetal nourishment, the infant has formed its body through essence and possesses spirit. In self-cultivation nourishment, the spirit enters Samadhi (meditative absorption) while qi guides it. Fetal nourishment relies on qi to gather spirit to activate it; self-cultivation nourishment relies on essence to accumulate qi to guide it. Fetal nourishment proceeds from qi generating essence, and essence generating spirit. Self-cultivation nourishment uses qi to collect spirit, and spirit to regulate essence. When the fetus-formed infant acquires spirit, it drives qi to send forth essence; thus, what emerges first is essence, which arises from the Prenatal to produce the Postnatal. In the self-cultivated infant, qi refines essence to preserve spirit, where spirit plays the dominant role; this supplements the Prenatal through the Postnatal. Ordinary people do not know how to protect and store essence; after adulthood, essence inevitably becomes deficient, and qi becomes weak. At the time of death, essence becomes rigid, qi falls, and spirit scatters along with the body, leading to becoming a ghost. Cultivators are good at cherishing themselves; upon success, essence becomes condensed, and qi becomes gathered. At the time of death, essence is complete, qi rises, and spirit follows out, preserving its spirituality. As stated in the *Book of Rites*, "The soul and qi ascend to Heaven, while the form and魄 (corporeal soul) return to Earth." As stated in the *Doctrine of the Mean*, "Though unseen and unheard, it permeates all things without omission." All these refer to this meaning. How can the infant exit? Its substance is extremely light, and its function is extremely spiritual. Using the extreme lightness of qi to send off the extreme spirituality of spirit, it naturally harmonizes with the light and clear Heaven that floats upward. Without distraction, how could it not exit to enter the Supreme Purity realm? In summary, the infant's ability to exit depends on the ability to enter Samadhi; entering Samadhi depends on the longevity of practice. The infant goes from drowsiness to clarity, from clarity to purity, from purity to lightness, from lightness to emptiness, from emptiness to spirituality, and from spirituality to divine spirit. Thus, it harmonizes with Heaven and Earth, illuminates with the Sun and Moon, follows the order of the Four Seasons, and aligns with the auspicious and inauspicious influences of spirits and ghosts. To make humanity harmonize with Heaven, what path is there other than this? The principle is exquisite, yet the practice seems mundane. People are accustomed to it and do not notice, thus ignoring it unconsciously. Do not be confused by heterodox schools, mistaking有形 (tangible) essence within the body for the infant. Tangible essence is merely a piece of flesh and blood within the body, not a light and pure substance; how can it reach the Supreme Purity World?! Secular terms like "flesh-body becoming a saint" mean achieving sainthood through the physical body. "Flying up with the entire household" means flying into the sky together with the whole house. Could the body and house truly be placed in the Upper Realm?! Even if such legends exist, they are all words attached by later generations. Examined by reason, they are hard to believe.