`Umar got some property in Khaibar and he came to the Prophet (ﷺ) and informed him about it. The Prophet said to him, "If you wish you can give it in charity." So `Umar gave it in charity (i.e. as an endowment) the yield of which was to be used for the good of the poor, the needy, the kinsmen and the guests.
Sahih al-Bukhari Book 55, Hadith 36
← Previous Hadith When `Umar got a piece of land in Khaibar, he came to the Prophet (ﷺ) saying, "I have got a piece of land, better than which I have never got. So what do you advise me regarding it?" The Prophet (ﷺ) said, "If you wish you can keep it as an endowment to be used for charitable purposes." So, `Umar gave the land in charity (i.e. as an endowments on the condition that the land would neither be sold nor given as a present, nor bequeathed, (and its yield) would be used for the poor, the kinsmen, the emancipation of slaves, Jihad, and for guests and travelers; and its administrator could eat in a reasonable just manner, and he also could feed his friends without intending to be wealthy by its means."

Sahih al-Bukhari Book 55, Hadith 35 Next Hadith → When Allah's Messenger (ﷺ) came to Medina, he ordered that a mosque be built. He said, "O Bani An- Najjar! Suggest me a price for the garden of yours." They replied, "By Allah, we will not ask its price except from Allah."

Sahih al-Bukhari Book 55, Hadith 37