Shiva Purana
जन्मान्तरेण संसिद्धः केनापि खलु हेतुना ॥ स्वपदप्रच्युतो दिष्ट्या प्राप्तो मुनिकुमारताम् ॥ ५ ॥
He was a great Siddha in his former birth who had fallen from his position for some reason. Fortunately he was born as the son of a sage.
english translation
janmAntareNa saMsiddhaH kenApi khalu hetunA ॥ svapadapracyuto diSTyA prApto munikumAratAm ॥ 5 ॥
hk transliteration by Sanscript