The ruling on that depends on the motive that makes him buy the land to be buried in.
If she wants to prepare a decent place for her burial, because she sees that the graveyards are neglected in her city, or because she sees that a number of people are buried in one place – as happens in some Muslim countries – or she wants to set that land aside as a waqf for burial for herself and other people, and other such aims that are acceptable in Islam, then in that case there is nothing wrong with it if she buys this piece of land and leaves a will instructing that she be buried there, because what she wants to achieve is acceptable according to sharee’ah, and the fiqhi principle says that “things are judged according to their purpose.”
Imam Ahmad (may Allaah have mercy on him) said: There is nothing wrong with a man buying the site of his grave and leaving a will instructing that he be buried there. ‘Uthmaan ibn ‘Affaan did that, as did ‘Aa’ishah and ‘Umar ibn ‘Abd al-‘Azeez (may Allaah be pleased with them all).
Al-Mughni (3/443). See also: Ahkaam al-Maqaabir fi’l-Sharee’ah by Dr. ‘Abd-Allaah al-Suhaybaani (23-28).
If she has no such purpose, and all she wants to do is to have a prominent grave and allocate a place separate from other people, then this purpose is not acceptable according to sharee’ah. There is nothing in the Qur’aan or Sunnah to indicate that such an action is permissible, rather in the principles of sharee’ah and the words of the scholars there is evidence to suggest that this is makrooh. For example:
1 – The fuqaha’ stated that it is mustahabb to be buried in the public graveyard so that the deceased may benefit from the du’aa’ of the believers who visit it, following the example of the Prophet (peace and blessings of Allaah be upon him), who buried those of his companions who died in the graveyard of al-Baqee’.
It says in al-Mawsoo’ah al-Fiqhiyyah (21/9):
The graveyard is the best place for burial, and that is in order to follow the Sunnah, and so that he may benefit from the du’aa’ of visitors. It is better to be buried in the best graveyard in the town, and it is makrooh to bury anyone in one’s house, even if the deceased is a small child. Ibn ‘Aabideen said: The same applies to burial in a private plot as is done by those who build schools and so on, and have a burial place built close to it. End quote.
See Radd al-Muhtaar (2/235); al-Majmoo’ (5/245) and Mughni al-Muhtaaj (2/52).
2 – Moreover, burial in land that is owned by the deceased harms the heirs, as it will prevent them from disposing of it, when there was sufficient room in the Muslim graveyard.
It says in al-Furoo’ by Ibn Muflih al-Hanbali (2/278):
If he leaves instructions to be buried in his own land, he should be buried with the Muslims, because that (instruction) harms the heirs. End quote.
3 – Moreover, leaving instructions that one be buried in private land carries the risk that in the future the grave may be tampered with, because the public graveyard is distinct and is known to all people, and no one can transgress upon it by building on it or digging and the like, as all the people will prevent their dead being dishonoured, whereas private land may be transgressed and subjected to people’s greed, as they may take the land and excavate the graves, etc.
4 – Burial in private land may lead to veneration and sanctification of the grave; people may think that there is something special about it or that this is the grave of one of the awliya’ (“saints”) and so on, so they may commit various kinds of shirk there or seek blessing in haraam ways, because of this person being buried separately from other people.
5 – Finally, there is the fear that the motive for leaving instructions that one be buried in a private plot is pride and the feeling that one is above being buried with other people in the same place, as can be seen in the graves of some kings and princes, who set aside private plots for themselves. It is known that pride is one of the greatest of sins but death usually breaks every proud and arrogant person, so the Muslim should not be like the arrogant or follow their ways.
From the above it is clear that buying land and leaving instructions that one be buried there for purposes other than those which are Islamically acceptable is not the best choice. The best option is to be buried with the Muslims and to expose oneself to the blessing of the du’aa’ of righteous Muslims.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said in Liqa’ al-Baab il-Maftooh (1/559):
The will does not have to be executed if the deceased left instructions that he is only to be buried in a certain place, rather he should be buried with the Muslims, because the earth is all the same, and if anyone among them died in any place, the Sahaabah (may Allaah be pleased with them) would bury him there. So these instructions do not have to be carried out, because there is no shar’i purpose behind them. End quote.
And Allaah knows best.