Sahih Muslim Book 5, Hadith Number 2225.
Chapter : The likeness of one who spends (in the path of Allah) and one who withholds.
It is narrated on the authority of Abu Huraira (that the Messenger of Allah) said: Of course the person who gives to the family a she-camel as a gift, which gives milk morning and evening equal to a large bowl, its reward (the reward of the gift) is great.