Vayupurana 1.21.p12

Vāyupurāṇa 1.21.p12

bhavasya putrajanmatvaṃ brahmaṇaḥ so'bhavadyathā.
brahmaṇaḥ padma yonitvaṃ rudratvaṃ śaṃkarasya ca .. 21.9 ..