The Book on General Behaviour (Kitab Al-Adab)
Muslim :: Book 25 : Hadith 5316
Jabir b. 'Abdullah reported that a child was born to a perfon amongst us and he gave him the name of Muhammad. Thereupon his people said: We will not allow You to give the name of Muhammad (to your child) after the name of Allah's Messenger (may peace be upon him). He set forth with his son carrying him on his back and came to Allah's Apostle (may peace be upon him', and said: Allah's Messenger a son has been born to me and I havegiven him the name after the name of Allah's Messenger (may peace be upon him), whereupon Allah's Messenger (may peace be upon him) said: Give him my name but do not give him my kunya, for I am Qasim in the sense that I distribute (the spoils of war) and the dues of Zakat amongst you.