Sahih al-Bukhari 4460
Sahih al-Bukhari · Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · The sickness of the Prophet (saws) and his death
Narrated Talha:
حَدَّثَنَا أَبُو نُعَيْمٍ ، حَدَّثَنَا مَالِكُ بْنُ مِغْوَلٍ ، عَنْ طَلْحَةَ ، قَالَ سَأَلْتُ عَبْدَ اللَّهِ بْنَ أَبِي أَوْفَى ـ رضى الله عنهما ـ أَوْصَى النَّبِيُّ صلى الله عليه وسلم فَقَالَ لاَ. فَقُلْتُ كَيْفَ كُتِبَ عَلَى النَّاسِ الْوَصِيَّةُ أَوْ أُمِرُوا بِهَا قَالَ أَوْصَى بِكِتَابِ اللَّهِ.
I asked `Abdullah bin Abu `Aufa "Did the Prophet (ﷺ) make a will? ' He replied, "No." I further asked, "How comes 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."