Sahih Muslim | Book 1 | Hadith Number 222

Narrated by Hakim b. Hizam
Hakim b. Hizam reported to 'Urwa b. Zubair that he said to the Messenger of Allah: Do you think that there is any thing for me (of he reward with the Lord) for the deed of religious purification that I did in the state of ignorance? Upon this he (the Apostle of Allah) said to him: You accepted Islam with all the previous virtues that you practised.