It is narrated from Hazrat Anas (may Allah be pleased with him) that once the Prophet (peace and blessings be upon him) was in Jannat al-Baqi', when a man called out to someone by saying "Abul Qasim." The Prophet (peace and blessings be upon him) turned around and looked back, so the man said, "I did not mean you." Upon this, the Prophet (peace and blessings be upon him) said, "You may name yourselves after my name, but do not take my kunya (Abul Qasim) as your kunya."