Bhagavad Gita 9.16
अहं क्रतुरहं यज्ञः स्वधाहमहमौषधम्। मन्त्रोऽहमहमेवाज्यमहमग्निरहं हुतम्।।9.16।।
ahaṃ kraturahaṃ yajñaḥ svadhāhamahamauṣadham| mantro'hamahamevājyamahamagnirahaṃ hutam||9.16||
aham kraturaham yajnah svadhahamahamaushadham mantro'hamahamevajyamahamagniraham hutam9.16
Meaning
Krishna is the ritual, the sacrifice, the offering to the ancestors, the healing herb, the sacred chant, the butter, the fire, and the act of offering. He is the totality of all worship.
मैं क्रतु हूँ; मैं यज्ञ हूँ; स्वधा और औषध मैं हूँ, मैं मन्त्र हूँ, घी हूँ, मैं अग्नि हूँ और हुतं अर्थात् हवन कर्म मैं हूँ।
This is verse 16 of 34 in Chapter 9 (Raja Vidya Raja Guhya Yoga) of the Bhagavad Gita.