Sahih Bukhari
Virtues of the Quran
Volume: 006 / Book Number: 061 / Hadith Number: 540
Narrated Talha:
I asked 'Abdullah bin Abi 'Aufa, "Did the Prophet make a will (to appoint his successor or bequeath wealth)?" He replied, "No." I said, "How is it prescribed then for the people to make wills, and they are ordered to do so while the Prophet did not make any will?" He said, "He made a will wherein he recommended Allah's Book."