Musnad Ahmad Hadith 25113

It is narrated from Aisha (may Allah be pleased with her) that on the day when the illness of the Prophet (ﷺ) began, the Prophet (ﷺ) came to me. I was having a headache, so I said, "Oh, my head!" The Prophet (ﷺ) jokingly said, "I wish that what is to happen would happen in my lifetime so that I could prepare you well and bury you." I said, "Is that your intention? You would become a bridegroom with another woman and spend the night with her that very day." The Prophet (ﷺ) said, "Oh, my head! Call your father and brother to me so that I may write a document for Abu Bakr, for I fear that someone will say something or someone will wish for something, claiming that he is more deserving of the caliphate, but Allah and all the Muslims will accept no one except Abu Bakr."