So Lord Śrī Kṛṣṇa is describing about the fruitive activities, sacrifice. In sacrifice we require so many things. Dravya-yajña. By material things... We require clarified butter, we require grains, we require mantra, chanting, and fire. So many things we require. So Lord says,
- ahaṁ kratur ahaṁ yajñaḥ
- svadhāham aham auṣadham
- mantro 'ham aham evājyam
- aham agnir ahaṁ hutam
"Now, all this paraphernalia for sacrificing a yajña, for performing a sacrifice—the fire, the butter, the clarified, the wood, and the mantra and other paraphernalia—everything is Myself. Everything I am." That's true, because everything is produced by His energy. Anything, whatever you take, that's a transformation of energy. Parasya brahmaṇaḥ śaktiḥ sarvedam akhilaṁ jagat: "Whatever you are seeing in the universal manifestation, they are simply manifestation of the different energy of the Supreme Lord." Just like in this room, this illumination is the energy of this light. Therefore we are seeing each, one another. Similarly, as the fire is placed in one place, but it distributes its heat and light, similarly, although the Lord is in His supreme abode, His energy is acting. The same example: just like the sun planet is far, far away, but its energy, sunshine, is all-over distributed, over the manifestation, material manifestation. So He's everything.