Shiva Purana
अस्य माता पूर्वभवे सपत्नीं छद्मनाहरत्॥ भक्षिता तेन पापेन ग्राहेणाऽस्मिन्भवे हि सा ॥ ५७॥
The mother of this boy had killed her co-wife in the previous birth. Hence due to that sin, she was devoured by the crocodile in this birth.
english translation
asya mAtA pUrvabhave sapatnIM chadmanAharat॥ bhakSitA tena pApena grAheNA'sminbhave hi sA ॥ 57॥
hk transliteration by Sanscript