But if a person, under the guise of waqf, blocks his children and heirs from selling the property; or if his debts mount and he declares his real estate a waqf in fear that it might be sold to satisfy rightful claimants; or if he dedicates it to his offspring yet deprives some of them while favouring others—for example, granting the daughters a share only as long as they remain alive, or preferring certain sons over others without a valid reason; or if he directs it to a cause that contains no element of piety or devotion, and the like—none of this is a sound waqf. It is merely placing the property under restriction in the name of waqf.

By acting in this manner he steps into the realm of wrongdoing instead of charity, because it is not in accordance with the will of Allah. Everything introduced outside Allah’s command is rejected—that is, it will be cast back upon its author.

From what has preceded, the lofty wisdom of waqf becomes evident: it is an act of kindness toward its beneficiaries, who are the most deserving of benevolence—either because they themselves are in need, such as the poor, orphans, widows, and those with no support; or because the community needs them, such as those striving in the path of Allah, teachers, students, and volunteers who serve the public good.

It is also a tremendous act of charity for the endower himself, for through this perpetual alms the reward continues to reach him after his deeds have ceased and his hopes have ended when he departs from this world to the Hereafter.

Hadith 1 (1)
ʿAbd Allah ibn ʿUmar reported:

ʿUmar acquired a piece of land at Khaybar, so he went to the Prophet ﷺ to seek his counsel concerning it and said, “Messenger of Allah, I have obtained a parcel of land at Khaybar; never have I gained any property that is more precious to me than it. What do you command me to do with it?” He replied, “If you wish, hold its principal in trust and give its yield in charity.”

ʿUmar therefore gave it in charity, stipulating that its principal would neither be sold nor inherited. He devoted its income to the poor, to relatives, for the emancipation of captives, in the path of Allah, to the wayfarer, and to the guest. There is no sin upon its custodian if he eats from it in a reasonable manner or feeds a friend, provided he does not seek thereby to accumulate wealth (in another wording: so long as he does not hoard from it).

Lexical notes
• “Land at Khaybar”: a region about 160 km north of Medina that is still cultivated and inhabited. It was home to the Jews until the Prophet ﷺ conquered it in 7 AH, allowing them to farm it until ʿUmar expelled them during his caliphate. The particular plot owned by ʿUmar was called Tamgh (pronounced “Tamgh,” with the first consonant vocalised and the second quiescent), which he had purchased from the lands of Khaybar.
• “yastaʾmiruhu”: he sought the Prophet’s advice regarding how to dispose of it.