Saṃkhyāvarta (संख्यावर्त्त): Commencement of Yajña at the Dawn of Tretāyuga
तस्मान्नान्वेति तद्यज्ञस्तपोमूलमिदं स्मृतम् / द्रव्यमन्त्रात्मको यज्ञस्तपस्त्वनशनात्मकम्
tasmānnānveti tadyajñastapomūlamidaṃ smṛtam / dravyamantrātmako yajñastapastvanaśanātmakam
Therefore that sacrifice does not measure up; this is remembered as rooted in austerity. Sacrifice consists of offerings and mantras, whereas austerity is of the nature of fasting.