Musnad Ahmad 27:1618

Yunus narrated to us, Hammad—meaning Ibn Zayd—narrated to us, Ayyub narrated to us, from Nafi’, from Ibn Umar, that Umar ibn al-Khattab acquired a piece of land from the Jews of Banu Harithah called Thamgh. He said: "O Messenger of Allah, I have acquired a precious property, and I wish to give it as charity." He said: "Make it an endowment (sadaqah) that is not to be sold, nor gifted, nor inherited. It shall be managed by those of sound judgment from the family of Umar. Whatever remains of its produce shall be spent in the way of Allah, the traveler, the freeing of slaves, the poor, the relatives, 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." Hammad said: Amr ibn Dinar claimed that Abdullah ibn Umar used to gift some of it to Abdullah ibn Safwan. He said: Hafsah gave a piece of land of hers as charity in the same manner, and Ibn Umar gave a piece of land of his as charity in the same manner, and Hafsah managed it.