Skandapurana 14.27.2

14.27.2

nihatya dānavānsaṃkhye kṛtvā snānaṃ sunirjhare ..
viṣṇuḥ prākṣālayattoyaṃ tena tanmedhyatāṃ gatam .. 2 ..

Having slain the Dānavas in battle, and having bathed in the beautiful mountain stream, / Viṣṇu washed [the discus] in the water; by that, it became pure. // 2