Shiva Purana
लब्ध्वा सर्वात्मना तस्य प्रसादात्परमेष्ठिनः ॥ ब्रह्मनारायणौ पूर्वं रुद्रः कल्पान्तरे ऽसृजत् ॥ १७ ॥
Having obtained it with all his heart by the grace of the Supreme Lord In the past, Lord Rudra created Brahma and Narayana in the next kalpa.
english translation
labdhvA sarvAtmanA tasya prasAdAtparameSThinaH ॥ brahmanArAyaNau pUrvaM rudraH kalpAntare 'sRjat ॥ 17 ॥
hk transliteration by Sanscript