Narrated Ibn 'Umar:
'Umar got some land in Khaibar, and when to the Prophet (ﷺ) and said: I have acquired land in Khaibar which I consider to be more valuable than any I have acquired ; so what do you command me to do with it ? He replied: If you wish, you may make the property as inalienable possession, and give its produce as sadaqah (charity). So 'Umar gave it as a sadaqah declaring that the property must not be sold, given away, or inherited : (and gave its produce as sadaqah to be devoted) to poor, relatives, the emancipation of slaves, Allah's path, travellers. The narrator Bishr added: "and guests". Then the agreed version goes: No sin being committed by the one who administers it if he eats something from it in a reasonable manner, or gives something to a friend, who does not make his own property. The narrator Bishr added: "(provided) he is not storing-up goods (for himself)".

Narrated Yahya b. Sa'id:
'Abd al-Hamid b. Abd 'Allah b. 'Abd Allah b. 'Umar b. al-Khattab copied to me a document about the religious endowment (waqf) made by 'Umar b. al-Khattab : In the name of Allah, the Compassionate, the Merciful. This is what Allah's servant 'Umar has written about Thamgh. He narrated the tradition like the one transmitted by Nafi'. He added: "provided he is not storing up goods (for himself)". The surplus fruit will be devoted to the beggar and the deprived. He then went on with the tradition, saying: If the man in charge of Thamgh wishes to buy a slave for his work for its fruits (by selling them), he may do so. Mu'iqib penned it and 'Abd Allah b. al-Arqam witnessed it : In the name of Allah, the Compassionate, the Merciful. This is what Allah's servant 'Umar , Commander of Faithful, directed, in case of some incident happens to him (i.e. he dies), that Thamg, Sirmah b. al-Akwa', the servant who is there, the hundred shares in (the land of) Khaibr, the servant who is there and the hundred sahres which Muhammad (ﷺ) had donated to me in the valley (nearly) will remain in the custody of Hafsah during her life, then the men of opinion from her family will be in charge of these (endowments), that these will neither be sold not purchased, spending (its produce) where they think (necessary on the beggar, deprived and relatives). There is no harm to the one in charge (of this endowment) if he eats himself, or feeds, or buys slaves with it.