Agniveshyagrihyasutra 3.7.3.1

3.7.3.1

yatho etadāhitāgnernirmāraṃ gacchataḥ pratikṛṣya prātaragnihotraṃ juhuyāt pratikṛṣyāmāvāsyāṃ yajeteti \

Now as to this: when an āhitāgni is passing into exhaustion, one should advance and offer the morning Agnihotra, and advance and perform the new-moon sacrifice.