Sahih Muslim Book 5, Hadith Number 2181.

Chapter : Beginning of spending for one’s own self, then for one’s family and then for relatives.

Abu Huraira reported Allah’s Messenger (may peace be upon him) as saying: Of the dinar you spend as a contribution in Allah’s path, or to set free a slave, or as a sadaqa given to a needy, or to support your family, the one yielding the greatest reward is that which you spent on your family.