Chapter 29: The Book of Endowments
It was narrated that Anas said: "When this Verse was revealed -' By no means shall you attain Al Birr (piety, righteousness--here it means Allah' s reward, i. e. Paradise), unless you spend (in Allah' s cause) of that which you love'- Abu Talha said: 'Our Lord will ask us about our wealth. I adjure you, O Messenger of Allah! I am giving my land to Allah.' The Messenger of Allah said: 'Make it for your relatives, Hassan bin Thabit and Ubayy bin Ka' b.'"
Sunan an-Nasa'i 3602