Skandapurana 1.4.11.147

1.4.11.147

nāradastvaṃtarikṣe ca jadadbījamidaṃ gṛṇan..
vajramidro liṃgamevaṃ viśvātmānaṃ ca nāma ca.. 13.147 ..

and Nārada in the sky, reciting [the name] “Seed of the World”;
Indra [worshipped] a diamond liṅga, reciting the name “Soul of the Universe”;