Bulugh al-Maram #1068

Narrated Ibn 'Umar (RA): 'Umar (RA) got some land in Khaibar and went to the Prophet (ﷺ) asking his command regarding it and said, "O Allah's Messenger, I have acquired a land in Khaibar which is the most valuable property that I have ever acquired." He replied, "If you wish you may make the property an endowment and give its produce as Sadaqah." So 'Umar (RA) gave the land as Sadaqah (in endowment on the condition) that must not be sold, inherited, or given away. And he gave its produce as Sadaqah to be devoted to the poor, relatives, the emancipation of salves, in Allah's Cause, for travelers and guests, and there is no sin upon the one who administers it if he eats something from it in a reasonable manner or gives something to a friend to eat, provided he does not store anything as goods (for himself). .