Sahih al-Bukhari — Conditions — Hadith No: 2737
Translation
Narrated Ibn `Umar:Umar bin Al-Khattab got some land in Khaibar and he went to the Prophet (ﷺ) to consult him about it saying, "O Allah's Messenger (ﷺ) I got some land in Khaibar better than which I have never had, what do you suggest that I do with it?" The Prophet (ﷺ) said, "If you like you can give the land as endowment and give its fruits in charity." So `Umar gave it in charity as an endowment on the condition that it would not be sold nor given to anybody as a present and not to be inherited, but its yield would be given in charity to the poor people, to the Kith and kin, for freeing slaves, for Allah's Cause, to the travelers and guests; and that there would be no harm if the guardian of the endowment ate from it according to his need with good intention, and fed others without storing it for the future