अहं वैश्वानरो भूत्वा प्राणिनां देहमाश्रितः।प्राणापानसमायुक्तः पचाम्यन्नं चतुर्विधम्॥
ahaṃ vaiśvānaro bhūtvā prāṇināṃ deham āśritaḥprāṇāpāna-samāyuktaḥ pacāmy annaṃ catur-vidham
Word by word
The verse says
Becoming the fire that digests, I live in the bodies of everything that breathes. Joined with the breath going out and the breath coming in, I cook the four kinds of food.
In plain words
This may be the least grand sentence anyone has ever spoken about God.
I am your digestion.
Vaiśvānara is the fire in the belly, the heat that turns food into a person. Krishna puts himself there, between your in-breath and your out-breath, doing the work while you think about something else.
Where you've felt this · in health
You ate lunch four hours ago and you have not thought about it since. In that time it has been broken down, sorted and sent to the places that needed it. You supervised none of it. If you had to, you would have got it wrong by the second step, and you would never have been able to think about anything else again.
Going deeper
Putting God in the stomach is a deliberate choice, and it is aimed at a particular kind of reader.
A mind that enjoys big ideas will happily park the divine at the edge of the universe, where it is safely far away and does not interrupt lunch. This will not allow that. Vaiśvānara, the fire of digestion, is about as unspiritual a location as exists.
There is a second point underneath it. Digestion is the clearest case of something essential happening in you that you neither do nor understand. You are not running it. You are also not separate from it. That is a small physical model of the whole relationship being described here.
And it corrects something people get wrong about this book. Eating, breathing and sleeping are not time off from the spiritual life. This says they are where it is already going on.