'Umar acquired land in Kheibar, so he came to the Prophet (PBUH) and asked him for advice regarding it. He said: I acquired a land in Kheibar. I have never acquired any wealth that is more precious to me than it. So what do you command me to do with it? The Prophet (PBUH) said: If you wish, you can keep it as an endowment to be used for charity. So 'Umar gave it in charity on the condition that it would not be sold, given away, or inherited, [and its yield] would be given to the poor, relatives, slaves, for the cause of Allah, travellers, and guests, and there is no blame on the one who is in charge of it if he eats from it reasonably or feeds a friend without profiting from it.