ahaḿ vaiśvānaro bhūtvā
prāṇināḿ deham āśritaḥ
pacāmy annaḿ catur-vidham

Translation of Bhagavad Gita 15.14

I am the fire of digestion in the bodies of all living entities, and I join with the air of life, outgoing and incoming, to digest the four kinds of foodstuff.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

According to Ayur-vedic shastra, we understand that there is a fire in the stomach which digests all food sent there. When the fire is not blazing there is no hunger, and when the fire is in order we become hungry. Sometimes when the fire is not going nicely, treatment is required. In any case, this fire is representative of the Supreme Personality of Godhead. Vedic mantras (Brihad-aranyaka Upanishad 5.9.1) also confirm that the Supreme Lord or Brahman is situated in the form of fire within the stomach and is digesting all kinds of foodstuff (ayam agnir vaisvanaro yo ’yam antah puruse yenedam annam pacyate). Therefore since He is helping the digestion of all kinds of foodstuff, the living entity is not independent in the eating process. Unless the Supreme Lord helps him in digesting, there is no possibility of eating. He thus produces and digests foodstuff, and by His grace we are enjoying life. In the Vedanta-sutra (1.2.27) this is also confirmed.

Sabdadibhyo ’ntah pratishthanac ca: the Lord is situated within sound and within the body, within the air and even within the stomach as the digestive force. There are four kinds of foodstuff—some are swallowed, some are chewed, some are licked up, and some are sucked—and He is the digestive force for all of them.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

Becoming vaisvanara, the fire in the stomach, taking shelter of the bodies of living entities, along with the prana and apana, which stimulate the fire, I digest the food of four types. The four types of food are: chewed with the teeth (bhaksyam), like roasted chick peas; savored by the tongue without using the teeth (bhojyam) such as soup; licked (lehyam) such as raw sugar; and sucked items (cosya), in which the chewed portion is discarded, such as sugar cane stick.

Commentary by Sri Ramanuja of Sri Sampradaya:

15.14 Becoming the ‘digestive fire’, or the fire of digestion, I function within the bodies of all living creatures. In union with various activities of ‘inward and outward breaths’, I digest the ‘four kinds of food’ eaten by individuals. These consist of foods to be chewed, sucked, licked and drunk. The Supreme Person who has the Soma, digestive fire etc., as his glory (Vibhuti) is here equated with Him by means of co-ordinate predication in the verses ‘Becoming the juicy Soma’ and ‘Becoming the digestive fire’. He now sets forth the reason for equating these glories with Himself.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Continuing on Lord Krishna affirms that His potency is vaisvanara or the digestive fire within the physical body that combing with the prana or exhalation and the apana or inhalation digests the four types of food eaten by jivas or embodied beings which are chewed, sucked, licked or drank. The first is that which is chewed by masticating the food into small pieces so it can be swallowed such as bread and vegetables. Next is that which can be licked by the tongue and swallowed without chewing like honey or molasses. After is that which can be sucked like the juice within sugarcane and finally is that which can be swallowed without chewing such as soups and liquid beverages. Hence they are all different.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

The Supreme Lord Krishna discloses that He is abiding in the physical body as the fire of digestion known as vaisvanarah assisting in the sustenance of all jivas or embodied beings.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Lord Krishna abides within the physical bodies of all jivas or embodied beings as vaisvanara the digestive fire which joining with the vital airs of prana or exhalation and apana or inhalation, digest the four kinds of food that are chewed, sucked, licked and drank. This is also confirmed in the Brhadaranyaka Upanisad V.IX.I beginning ayamagnirvaisvanaro yo ayamantah puruse meaning: From the purusa or Supreme Lord comes the fire of digestion known as vaisvanara by which food that is eaten is digested.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

15.14 Bhutva, taking the form of; vaisvanarah, Vaisvanara, the fire in the stomach, mentioned in such Upanisadic texts as, ‘This fire that is within man and digests the food (that is eaten) is Vaisvanara’ (Br. 5.9.1); becoming that Vaisvanara, and asritah, residing in, entering; deham, the bodies; praninam, of creatures, of living beings; aham, I Myself; prana-apana-samayuktah, in association [i.e. kindled, inflamed, by Prana and Apana.] with Prana and Apana; [Prana-that vital force which goes upward and has its seat really in the heart (cf. Tai. Br., but it said to be located at the tip of the nose since its presence is directly felt there. Apana-that vital force which goes downward, below the navel, and has its seat in the organs of excertion.-Tr.] pacami, digest; the caturvidham, four kinds of; annam, food-those that are eaten by masticating, swallowing, sucking and licking. The eater is the fire called Vaisvanara, and the eaten is the food Soma. One who looks upon all that there is as being these two, fire and Soma, is not affected by the impurity of food. Further,

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

15.12-14 Yad aditya-etc. upto caturvidham. While clarifying the role [of the Lord] as the Creator, Sustainer and Destroyer – a role that has been indicated in the Tenth Chapter – by [the description of Him as identical with] the triple luminories like the sun etc., our venerable preceptor has rightly said : The present passage declares that the power, the pentad of elements has [both] collectively and individually, to sustain the world, is the Absolute power of the Bhagavat Himself. For instance : The sunlight has the power of illumining and sustaining, because the twin elements of the fire and the earth are one [with the Bhagavat]. This has been started by the twin hemistitches ‘[That light] which is found in the sun etc.’ and ‘And by penetrating the earth etc.’ The moon-light is illumining and nourishing because of its assoication of the elements of the earth, the water and the fire [with the Bhagavat]. That has been stated by the portion ‘[That light] which is in the moon’ and by the hemistitch ‘Being the sapful moon I nourish all plants’. The light of fire is, however, of the nature of illumining, parching, burning, sweating and ripening (or cooking). It is so because of the association of the elements, the earth, the water, the fire and the wind [with the Bhagavat]. The same has been said here by the portion, ‘[That light] which is in the fire’ and also by the [entire verse] ‘I, being the digestive fire etc.’ But the [element] ether is no doubt all pervaisve (inclusive), because it is of the form of room which is nothing but awareness. Therefore, having so far explained the nature [of the Absolute Self] as the object of knowledge, now, with a view to show the Self to be conscious of the freedom that remains as a background (or substratum) of that very nature of object of knowledge; to be of transcending nature; to be the Supreme Lord; to be independent in all knowledges; and to be the Creator of all; [the Lord] says –

Sanskrit Shloka Without Transliteration Marks:

aham vaisvanaro bhutva
praninam deham asritah
pacamy annam catur-vidham

Sanskrit to English Word for Word Meanings:

aham — I; vaiśvānaraḥ — My plenary portion as the digesting fire; bhūtvā — becoming; prāṇinām — of all living entities; deham — in the bodies; āśritaḥ — situated; prāṇa — the outgoing air; apāna — the down-going air; samāyuktaḥ — keeping in balance; pacāmi — I digest; annam — foodstuff; catuḥ-vidham — the four kinds.