What is the form of the legitimate laḥd (niche grave), and is it permissible after a period of time to open the laḥd and place the body of another person, and is it obligatory to divide the area of the burial plot between men and women, or are bodies placed according to the order of death?

The practice of Muslims has been that the graveyard is an endowment for all, with no distinction between rich and poor, and it was not customary for each family to have its own private graveyard.

Among the corrupting consequences of this [private ownership] are building on graves, boasting about them, writing on them, and constructing reception rooms next to them, all of which are reprehensible acts not mentioned in Islamic law.

There is no blame upon one who is compelled to purchase a private grave for himself and his family, and there is no blame in building a fence around the graveyard to protect it, provided that the construction does not exceed what is necessary.

The basic principle regarding graves is the prohibition of building on them, plastering them, or sitting on them, due to the Prophet's (peace and blessings be upon him) prohibition of such acts, and his command to level elevated graves.

The lahd (niche in the side of the grave) should be deep enough to prevent floods and wild animals. It is recommended to be deep. There is no harm in women's graves being next to men's graves, but they should not be placed together in one grave except out of necessity.