Padma Purana 4.8.23

Padmapurāṇa 4.8.23

dhārayāmyahamevādriṃkūrmarūpeṇasarvataḥ
ityuktvābhagavānviṣṇuraṃtarddhānaṃjagāmasaḥ
jagmuḥsurāsurāḥsarvesamudramathanaṃdvija

iti śrīpādmemahāpurāṇebrahmakhaṃḍesamudramathanodyogonāmāṣṭamo'dhyāyaḥ