Matsyapurana 51.17

51.17

ityete vai nadīputrā dhiṣṇyeṣu pratipedire
teṣāṃ viharaṇīyā ye upastheyāśca tāñśṛṇu
vibhuḥ pravāhaṇo 'gnīdhras tatrasthā dhiṣṇavo 'pare //

All the sons of the rivers made friends with these Dhiṣṇyas. Listen now about the Viharaṇîyas (those which are removable from the altar) and Upastheyas (those which are fixed in their places and worshipped there), amongst them. Vibhu, Pravâhana and Âgnidhra are fixed in their altars, while the remaining Dhiṣṇus are shifting and moving, and taken from their places when some auspicious occasions arise. Hear the names of Anirdeśya and Anvârya Agnis, in order.—17-18.