Sahih Muslim Book 30, Hadith Number 5862.
Chapter : The merits of Yousuf (Joseph) (peace be upon him).
Abu Huraira reported: It was said to Allah’s Messenger (may peace be upon him) as to who was the most worthy of respect amongst people. He said: The most God-conscious amongst you They said: It is not this that we are asking about, whereupon he said: Then he is Yusuf, the Apostle of Allah and the son of Allah’s Apostle, Ya’qub, who was also the son of Allah’s Apostle, the friend of Allah (Ibrahim) They said: This is not what we are asking you. He said: You mean the tribes of Arabia? Those who are good in pre-Islamic days are good in Islam (after embracing Islam) when they get an understanding of it.