Is a Muslim who dies without writing a will forbidden from addressing the dead in the grave?

A will is permissible and becomes obligatory for a Muslim if they have a legal right that they fear will be lost, based on the Prophet's (peace be upon him) saying: "It is not right for a Muslim who has something to bequeath to spend two nights without having his will written down with him." It is recommended to make a bequest to relatives, the poor, and the righteous, as long as it does not harm the heirs. It is forbidden if it harms them, disliked for a poor person who has needy heirs, and permissible for the wealthy. The pious predecessors used to write their wills with specific phrases, but adherence to them is not obligatory.