As for the account of the document that the Messenger of Allah—peace and blessings be upon him—intended to write, it has been reported in explicit terms. In the two Sahīhs, Aisha—may Allah be pleased with her—said:
“The Messenger of Allah—peace and blessings be upon him—said during his illness:
‘Call your father and your brother to me so that I may write a document. I fear that someone may aspire to it and another may say, “I have the greater right.” Yet Allah and the believers will refuse anyone other than Abu Bakr.’”
This hadith was cited earlier at 1/492 and 511.
In [Sahīh] al-Bukhārī (1), al-Qāsim ibn Muhammad said:
“Aisha said, ‘Oh, my aching head!’ The Messenger of Allah—peace and blessings be upon him—replied, ‘If that were to happen while I am still alive (2), I would seek forgiveness for you and supplicate for you.’
“Aisha said, ‘Oh, what a calamity! By Allah, I believe you wish me dead. If that happened, you would spend the latter part of the day being intimate with one of your wives.’
“The Messenger of Allah—peace and blessings be upon him—said, ‘No, it is I who should say, “Oh, my aching head!” I had indeed considered (3) sending for Abu Bakr and his son and leaving instructions (4), lest claimants make claims or aspirants entertain hopes. But Allah would forestall that, and the believers would refuse it.’” (5).
In Sahīh Muslim (6), [Ibn] (7) Abī Mulayka said:
“I heard Aisha,