no. 640 for the year 2008 which includes the following:
 We have a small mosque in our neighborhood which does not accommodate all of those who wish to offer prayers in it. It is administered by the Ministry of Religious Trust under decree no.16 for the year 2000 CE. My house is adjoined to the mosque's restrooms which comprises 4 cubicles. I want to exchange the land on which the restrooms are built (which does not exceed 18 square meters) for 200 square meters of my own land to build an entryway to my house. The piece of land I will give to the mosque lies in the direction of the qibla and will facilitate expansion of the mosque.
Before concluding the contract, I proceeded to the Endowments Directorate and submitted my offer verbally. I was told that my offer will be declined unless I build new restrooms with my own money. I was further told that after constructions have been completed, a committee from the Municipal Directorate will inspect the new structure.
I built six cubicles in addition to a place for ablution—all built to high standards. I also laid the foundations for the expansion of the mosque on the remaining area of land as shown in the attached diagram. In this manner, the mosque will become a well ventilated single big structure. I then proceeded to the Ministry of Religious Trust for a formal approval of the exchange only to learn that my offer will be rejected for reasons of public interest except after the matter is referred to his eminence the Grand Mufti of Egypt for approval. In view of this, I request your opinion to submit to the ministry of Religious Trust.

The principle is that it is impermissible to substitute an endowment for another except for a genuine benefit determined by the courts and not by the layman. Some scholars have maintained that it is permissible to substitute an endowment, disregarding the conditions laid down by the endower, with the permission of the courts though only if this is in the interest of the endowment itself.  Other scholars strictly forbid this for fear that the administrators may forfeit the endowment or its substitute. However, when the substitution can be safely implemented and it is possible to prevent any squandering on the part of the administrators, the court is entitled to rule in favor of substituting the entire endowment or part of it if the interest lies therein.

Textual evidence
Ibn Nujaim, the author of Al-Bahr Al-Ra`iq Sharh Kinz Al-Daqa`iq said, "According to Abu Yusuf, it is permissible to substitute an endowment for another which generates more revenues and is located in a better area. Otherwise, it is impermissible." Quoting fom Sharh Mandhumit Ibn Wahban, Ibn Nujaim further said, "Is substitution permissible if the endower stipulates that the endowment is not to be replaced with another, if its administrator is dismissed before substitution is implemented or is dismissed because of his decision to substitute the endowment?' Al-Tarsusi said, "There is no text on this matterand according to the opinion adopted by the Hanafi School of Jurisprudence, the court is to substitute the endowment if benefit lies therein because the condition stipulated by the endower against any court interference is null and void. The court has the authority to decide due to its overriding knowledge and case evaluation. Because the [above] condition involves forfeiting the interests of the beneficiaries and suspending the endowment, it is considered ineffectual and therefore unacceptable."
There is no doubt that what is meant here by benefit and maslahah mu'tabara (recognized public interest) is the exclusive interest of the mosque. The court is the only instrument entrusted with deciding whether there is a real necessity for replacing the endowment.    Allah the Almighty knows best.