Sahih Bukhari

Narrated Talha:I asked `Abdullah bin Abu `Aufa ""Did the Prophet (ﷺ) make a will? ' He replied, ""No."" I further asked, ""How come is it that the making of a will was enjoined on the people or that they were ordered to make it? "" He said, ""The Prophet (ﷺ) made a will concerning Allah's Book.""