Astanga Hrudaya
सारस्तु सप्तभिर्भूयो यथास्वं पच्यतेऽग्निभिः। रसाद्रक्तं ततो मांसं मांसान्मेदस्ततोऽस्थि च॥६२॥
Action of seven tissue fires on the essence of the food: The sara (essence) undergoes further cooking (transformation) by the seven agni of their own, (dhtvagni present in each dhatu). Sequential formation of tissues from one another: From rasa (lymph), rakta (blood) gets formed, then mamsa (muscle) (from rakta), from muscle medas (fat) gets formed, then asthi (bones) from fat; from bones;
english translation
sArastu saptabhirbhUyo yathAsvaM pacyate'gnibhiH। rasAdraktaM tato mAMsaM mAMsAnmedastato'sthi ca॥62॥
hk transliteration by Sanscript