Shiva Purana
यस्मात्सांबो महादेवः प्रददौ पुत्रमात्मनः ॥ तस्माज्जांबवतीसूनुं सांबं चक्रे स नामतः ॥ २५ ॥
Since it was Śiva accompanied by Ambā, who blessed him with a son, he named Jāmbavatī’s son Sāmba.
english translation
yasmAtsAMbo mahAdevaH pradadau putramAtmanaH ॥ tasmAjjAMbavatIsUnuM sAMbaM cakre sa nAmataH ॥ 25 ॥
hk transliteration by Sanscript