Shiva Purana
पुत्रान्वै कल्पयामास स्वयमेव पितामहः ॥ तेषां विरोधो देवानां दानवानां महानृषे ॥ ३ ॥
The grandfather himself conceived his sons O great sage there was a conflict between the gods and the demons.
english translation
putrAnvai kalpayAmAsa svayameva pitAmahaH ॥ teSAM virodho devAnAM dAnavAnAM mahAnRSe ॥ 3 ॥
hk transliteration by Sanscript