Musannaf Ibn Abi Shayba 35:65

Ibn ‘Ulayyah narrated to us, from Ibn ‘Awn, from Nafi’, from Ibn ‘Umar, who said: ‘Umar acquired land in Khaybar. He came to the Prophet (may Allah bless him and grant him peace) and asked him about it, saying: "I have acquired land in Khaybar, and I have never acquired property more precious to me than it. So what do you command me to do with it?" He said: "If you wish, you may withhold its essence and give its produce as charity." He said: So ‘Umar gave it as charity, with the condition that its essence is not to be sold, nor given away, nor inherited. He gave it as charity to the poor, the relatives, the freeing of slaves, in the way of Allah, the wayfarer, and the guest. There is no blame upon the one who manages it if he eats from it in a reasonable manner, or feeds a friend, without accumulating wealth from it.