Shiva Purana
ऋषय ऊचुः ॥ तत्र स्थितो बहुयुगं ब्रह्मलोके स रेवतः ॥ युवैवागान्मर्त्यलोकमेतन्नः संशयो महान् ॥ ४१॥
The sages said:— Raivata stayed in Brahmā’s region for many Yugas. He returned to the mortal world as a young man. This is my great doubt.
english translation
RSaya UcuH ॥ tatra sthito bahuyugaM brahmaloke sa revataH ॥ yuvaivAgAnmartyalokametannaH saMzayo mahAn ॥ 41॥
hk transliteration by Sanscript