Shivapurana 7.2.21.41

Śivapurāṇa (complete text) 7.2.21.41

punardevaṃ śivaṃ natvā tato nāmāṣṭakaṃ japet |
śivo maheśvaraścaiva rudro viṣṇuḥ pitāmahaḥ ||