Sahih Bukhari Volume 002, Book 024, Hadith Number 517.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 24. Obligatory Charity Tax (Zakat)
Narated By Hakim bin Hizam : I said to Allah's Apostle, "Before embracing Islam I used to do good deeds like giving in charity, slave-manumitting, and the keeping of good relations with Kith and kin. Shall I be rewarded for those deeds?" The Prophet replied, "You became Muslim with all those good deeds (Without losing their reward)."