Bhagwad Gita
Chapter 9, Verse 16
अहं क्रतुरहं यज्ञः स्वधाऽहमहमौषधम्।
मंत्रोऽहमहमेवाज्यमहमग्निरहं हुतम्।।9.16।।
But it is I who am the ritual, I the sacrifice, the offering to the ancestors, the healing herb, the transcendental chant. I am the butter and the fire and the offering.