Endowing land for the construction of a mosque and selling the land

Question:
May Allah reward you with good. This questioner says: I have a piece of land in the city of al-Turabah. I have decided to make it an endowment (waqf) for Allah the Exalted, and I have informed my family of this. I had also pledged to myself to build a mosque on this land. When I asked about it, I was told that I am obligated to build a house for the mu'adhdhin (the one who calls to prayer) and another for the imam, but I am unable to do so. Is it permissible for me to sell this land, take its price, and build a mosque with it in another place, either inside or outside Saudi Arabia? Please note that I work outside the Kingdom.

Answer:
If you have endowed the land for a mosque to be built on it, you are bound by it. If the endowment has issued from you by your tongue, and you have said, "This land is an endowment on which a mosque is to be built," it has exited your ownership and become an endowment on which a mosque is to be built. You are not obligated to build the mosque; rather, the land has exited your ownership and become an endowment. However, if you have made a vow (nadhr) to Allah that you will build a mosque on it, you are obligated to fulfill the vow if you are able. As for merely having endowed the land, you are not obligated to build the mosque; other Muslims will build on it. If you say, "This land is an endowment on which a mosque is to be built," it has exited your ownership, and the Muslims, the state, or the benefactors will build on it if there is a need for a mosque to be built there. As for you, you are not obligated unless you have vowed that you yourself will build a mosque there. In that case, you are obligated to fulfill your vow with the ability to do so. You are not obligated to build a house for the imam or the mu'adhdhin. The house for the imam or the mu'adhdhin is a separate matter. If you have vowed land for a mosque to be established, or vowed to build a mosque, you are not obligated to build a house for the imam or the mu'adhdhin unless you have specified this in the vow. If you said, "I have a vow upon me to Allah to build a mosque and to build with it a house for the imam or the mu'adhdhin," you are obligated, based on the saying of the Prophet (peace and blessings be upon him): "Whoever vows to obey Allah, let him obey Him." But if you have vowed only a mosque, you are not obligated to build the house for the imam or the mu'adhdhin; rather, others will build it.