“It is a sin to spit in a Masjid, and the removal of the sin is to cover it over.”
“Whoever shall enter a Masjid, let him enter it for a good object, namely, to learn something himself or to teach others. For he ranks as an equal with him who fights in the cause of God, who thus enters a Masjid; but he who enters a Masjid on any other account, is like unto a man who covets the property of another. Verily, a time will come when men will attend to worldly matters in a Masjid. But sit ye not with such.”
“Do not prevent your women from coming to the Masjids, but their homes are better for them.”
“Do not read poetry in a Masjid, and do not buy and sell there, nor sit in a circle talking before prayers on a Friday.”
“The prayers of a man in his own house are equal to the reward of one prayer, but prayers in a Masjid near his home are equal to twenty-five prayers, and in a Jāmiʿ (or central mosque), they are equal to five hundred prayers, and in Jerusalem to fifty thousand, and in my Masjid (at al-Madīnah) fifty thousand, and at the Kaʿbah, one hundred thousand.”
The Muslim law regarding the erection and endowment (waqf) of Masjids, as contained in Sunnī and Shīʿah works, is as follows. According to the Sunnīs:—
When a person has erected a Masjid, his right therein does not cease until he has separated both the area occupied by the Masjid and also the road and entrance thereunto from his own private property.
If a person build a Masjid, his right of property in it does not cease so long as he does not separate it from his private property, and give general permission to the people to come and worship in it. But as soon as he separates it from his property and allows even a single person to say his prayers in it, his right to the property devoted to God as a mosque ceases.
When a trustee or superintendent (mutawallī) has been appointed for a Masjid, and delivery of the property has been made to him, the Masjid ceases to be private property. So, also, when delivery of it is made to the Qāẓī, or his deputy.
If a person appropriate ground for the purpose of erecting a Masjid, he cannot afterwards resume or sell it, neither can it be claimed by his heirs and inherited, because this ground is altogether alienated from the right of the individual, and appertains solely to God.