Abu Dawud
General Behavior
Book Number: 036 / Hadith Number: 5121
Narated By Bakr ibn al-Harith al-Anmari : Bakr went to the Prophet (pbuh) and said: Apostle of Allah! to whom should I show kindness? He said: Your mother, your sister, your brother and the slave whom you set free and who is your relative, a due binding (on you), and a tie of relationship which should be joined.