Abu Asim said that Sufyan, expressing his opinion, stated: A man used to worship for forty years first, then he would set out in search and pursuit of knowledge.
Hadith Takhrijاس قول کی سند صحیح ہے۔ دیکھئے: [المحدث الفاصل 51]
Brief Explanation
(Commentary on Ahadith 375 to 383) Abu Asim: He is Dahhak bin Makhlad. (The Messenger of Allah sallallahu alayhi wa sallam was granted prophethood at the age of forty years.)