Bhagavad Gita, Chapter 15, Verse 14

Abiding in the body of living beings as the fire Vaishvânara, I, associated with Prâna and Apâna, digest the fourfold food.

Something as ordinary as digestion is named here as real, active divine presence, not a purely mechanical process.

Naming this presence as the actual fire that breaks down food grounds the abstract claim of pervading everything in something concretely bodily. Real, everyday biology becomes evidence of something larger.