Matsyapurana 110.10

110.10

yajante kratubhir devās tathā cakradharā nṛpāḥ
tataḥ puṇyatamaṃ nāsti triṣu lokeṣu bhārata //

There the incarnate Vedas and yajñas (sacrifices), O, Yudhiṣṭhira !, adore Brahmâ, as do ascetics, the sages. The Devas, and the kings adore Prayâga by performing sacrifices. There is nothing more sacred than Prayâga in all the three worlds.—9-10.