2/575 – On his authority, the Messenger of Allah ﷺ said: “No Muslim who possesses something to bequeath should sleep two nights without having his will written and kept with him.” Agreed upon; this is al-Bukhari’s wording.

In another narration recorded by Muslim: “…should sleep three nights.”

Ibn ʿUmar said, “From the moment I heard the Messenger of Allah ﷺ say this, not a single night has passed but that my will is with me.”

[Explanation]
The author—may Allah have mercy on him—then cited the hadith of Ibn ʿUmar—may Allah be pleased with them—where the Prophet ﷺ said: “No Muslim who has something to bequeath should sleep two nights without having his written will with him.” In other words, he ought not to let two nights pass before writing down the bequest he intends to make. From the time Ibn ʿUmar—may Allah be pleased with him—heard these words from the Messenger of Allah ﷺ, he never spent a single night unless his will was already written.

The waṣiyyah (will) is a binding instruction made for after one’s death. A person may, for example, entrust someone to dispose of part of his wealth, appoint a guardian over his minor children, or assign any other matter that remains under his control after death; all of this falls under the heading of the written will.