Astanga Hrudaya
सन्धुक्षितः समानेन पचत्यामाशयस्थितम्। औदर्योऽग्निर्यथा बाह्यः स्थालीस्थं तोयतण्डुलम्॥५६॥
then the audaryagni (jatharagni -digestive fire) activated by Samanavata cooks the food present in the Amasaya (stomach) just like external fire cooks the rice and water kept in the pot
english translation