Umar bin Khattab got some land in Khaibar and he went to the Prophet ﷺ to consult him about it saying, "O Messenger of Allah 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 ʿUmar gave it in charity as an endowment on the condition that 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."  

أَنَّ عُمَرَ بْنَ الْخَطَّابِ أَصَابَ أَرْضًا بِخَيْبَرَ فَأَتَى النَّبِيَّ ﷺ يَسْتَأْمِرُهُ فِيهَا فَقَالَ يَا رَسُولَ اللَّهِ إِنِّي أَصَبْتُ أَرْضًا بِخَيْبَرَ لَمْ أُصِبْ مَالاً قَطُّ أَنْفَسَ عِنْدِي مِنْهُ فَمَا تَأْمُرُ بِهِ قَالَ إِنْ شِئْتَ حَبَسْتَ أَصْلَهَا وَتَصَدَّقْتَ بِهَا قَالَ فَتَصَدَّقَ بِهَا عُمَرُ أَنَّهُ لاَ يُبَاعُ وَلاَ يُوهَبُ وَلاَ يُورَثُ وَتَصَدَّقَ بِهَا فِي الْفُقَرَاءِ وَفِي الْقُرْبَى وَفِي الرِّقَابِ وَفِي سَبِيلِ اللَّهِ وَابْنِ السَّبِيلِ وَالضَّيْفِ لاَ جُنَاحَ عَلَى مَنْ وَلِيَهَا أَنْ يَأْكُلَ مِنْهَا بِالْمَعْرُوفِ وَيُطْعِمَ غَيْرَ مُتَمَوِّلٍ قَالَ فَحَدَّثْتُ بِهِ ابْنَ سِيرِينَ فَقَالَ غَيْرَ مُتَأَثِّلٍ مَالاً