While the Prophet (ﷺ) was in the market, somebody called, "O Abul-Qâsim." The Prophet (ﷺ) turned to him. The man said, I have called to this (i.e. another man)." The Prophet (ﷺ) said, "Name yourselves by my name but not by my Kuniya (name)." [1] (In Arabic world it is the custom to call the man as the father of his eldest son, e.g. Abul-Qâsim.). [3:331-O.B]