At the end of Vaisika Daśapūrṇayāga, it is a custom to offer dakṣiṇā (daksina; what is given to the priests as a token of honour) to the Ṛttvik(s) (Rittwik; priest of a Vedic ritual). The four Ṛttvik(s) are given an immesurable amount of rice, so that they can cook it on their own. That cooked food is called odana.  The Adhvaryu  puts a container made of copper or brass to dakṣiṇāgni (dakshinagni), and cooks that anna. This act of cooking is called Anvāhārya-pacana (Anvaharya-pachana) and that cooked rice is known as Anvāhārya. And this cooked rice itsed is the dakṣiṇā of Daśapūrṇamāsa-yāga (Dasapurnamasayaga), that is, after offering this dakṣiṇā, the yajña(yajna) becomes complete. Only dakṣiṇāgni can be used for the cooking of Anvāhārya, so this agni is also called Anvāhārya agni.