It was narrated from Azhar As-Samman, from Ibn 'Awn, from Nafi', from Ibn 'Umar, that 'Umar acquired some land at Khaibar. He came to the Prophet and consulted him about that. He said:
If you wish, you may 'freeze' it and give it in charity. So he 'froze' it, stipulating that it should not be sold, given as a gift or inherited, and he gave it in charity to the poor, relatives, slaves, the needy, wayfarers and guests. There is no sin on the administrator if he eats from it on a reasonable basis or feeds a friend with no intention of becoming wealthy from it.