Kurmapurana 2.2.18

Kūrmapurāṇa 2.2.18

paśyanti ṛṣayo 'vyaktaṃ nityaṃ sadasadātmakam /
pradhānaṃ prakṛtiṃ buddhvā kāraṇaṃ brahmavādinaḥ //