The scholars, by consensus, have said that burying the dead is a “Faradh Kifaya” and that it is better to perform it as soon as possible.
The minimum grave requirements: a hole in the ground that would completely conceal the dead body, preventing its odor from reaching people, and to protect it from wild beasts.
It is recommended to dig wider and deeper. There are two different shapes of graves– Lahd and Shiqq, with Lahd being the better of the two. Lahd means that a concave hollow is dug into the wall of the grave that faces the Qiblah. This hollow should be wide and deep enough to house the body. Shiqq, on the other hand, means to dig the usual grave consisting of a rectangular hole in the ground where the body is placed with a ceiling over it that protects it from the dirt. It has been the practice during the life of the messenger (S.A.W.) and throughout the time of his blessed companions and their followers to bury the Muslim in Muslims cemeteries.
Furthermore, the body is laid in the grave on its right side facing the “Qiblah”. The person laying the body should say: “In the name of Allah, and by the way of the messenger of Allah – or by the tradition of the messenger of Allah”, while laying the body. He then must untie all the ties of the shroud when the prophet (S.A.W.) laid a dead body in the grave, he said:” In the name of Allah, and by the way of the messenger of Allah or by the tradition of the messenger of Allah.” [Reported by Imams Ahmad, Abu Dawood, At-Tirmithi, and others]
It is good for those attending the funeral to throw – three times each -a handful of dirt. They should throw the dirt to the side of the grave where the head has been placed. The prophet (S.A.W.) once prayed the Janazah (funeral) prayer, then went to the dead’s grave and threw dirt on it from the side of the body’s head, three times. [Reported by Imam Ibn Majah]
Another thing that is highly recommended to do is to ask Allah (SWT) forgiveness for the dead person upon finishing the burial and to take advantage of the gathering to advise and preach to people about the Hereafter. The prophet (S.A.W.) used to say when he is done with the burial: “Ask Allah forgiveness for your brother and ask Him to confirm his heart because he is being questioned now.” [Reported by Imams Abu Dawood and Al-Hakim]
Also, Al-bara’ Bin Azib (R.A.) narrated: “We went out with Allah’s Messenger (S.A.W.) with the funeral of a man of the Ansaar (The native residents of Madinah) and we came to the grave and the slot in the side of the grave (Al-Lahd) had not been dug out yet, so Allah’s messenger (S.A.W.) sat and we sat around him as if we had bird upon our heads (very alert) and in his hand he had a stick with which he was striking the ground. Then he raised his head and said, “Seek Allah’s refuge from the punishment of the Grave,” two or three times. Then he said, “When the Believing servant is leaving this world and going on to the Hereafter, angels with bright faces -as if their faces were the sun – descend upon him…” [An authentic Hadith reported by Imams Ahmed, Abu Dawood and Al Hakm]
It is recommended to raise the grave about 8 inches above ground so that it will be recognized. Higher than 8 inches is not allowed. It is allowed, however, to mark the grave with a rock, piece of wood …etc to distinguish it. The prophet (S.A.W.) marked the grave of Othman Ibn Math’oon (R.A.) with a rock and said: “with it I recognize the grave of my brother and bury next to him those who die from my family.” [Reported by Imam Abu Dawood]
It is not permissible to cement the grave or to construct on top of it, to write on it, or to turn the area around it into a mosque. Also, not allowed, is kissing it, going around it as if performing a ritualistic act, and smoking it with perfume. The prophet Muhammad (S.A.W.) forbade cementing the graves with mortar, the writing on the graves, and the building of structures on top of them. [Reported by Imams Muslim and others]
Also, the Prophet (ﷺ) said: “Do not make your houses graves, and do not make my grave a place of festivity. But invoke blessings on me, for your blessings reach me wherever you may be.” [Reported by Abu Dawud]. And he said: “Do not sit on the graves and do not pray facing towards them.” [Related by Muslim].
In addition, it is a must to respect the grave by not sitting on it or walking on top of it. Two Hadiths are cited here. When the prophet (S.A.W.) saw Omar Ibn Hizam leaning against a grave, he said:” Do not harm the occupant of this grave.” [Reported by Imam Ahmad]
The second Hadith the prophet (S.A.W.) said: “It is better for the one of you to sit on a piece of burning coal that would burn his clothes then penetrate to his flesh, than to sit on a grave.” [Reported by Imam Muslim and others]