Sahih Muslim Book 42, Hadith Number 7108.

Chapter : Benevolent Treatment to the Widows, Orphans, the Poor.

Abu Huraira reported that Allah’s Messenger (may peace be upon him) said: One who looks after the orphan whether he is his relative or not, I and he would be together in Paradise like this, and Malik (explained it) with the gesture by drawing his index finger and middle finger close together.