Bhagavad Gita 9.16
अहं क्रतुरहं यज्ञः स्वधाहमहमौषधम् |
मन्त्रोऽहमहमेवज्यमहम्ग्निरहं हुतम्
Translation
It is I who am the Vedic ritual, I am the sacrifice, and I am the oblation offered to the ancestors. I am the medicinal herb, and I am the Vedic mantra. I am the clarified butter, I am the fire and the act of offering.