Sahih Bukhari Volume 004, Book 056, Hadith Number 737.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 56. Virtues and Merits of the Prophets (PBUH) and his Companions
Narated By Anas : While the Prophet was in the market, a man called (somebody), "O Abu-l-Qasim!' The Prophet turned to him and said "Name yourselves after me but do not call yourselves by my Kuniya."