The Messenger of Allah ﷺ said to me during his illness, "Call Abu Bakr and your brother for me so that I may write a document, for I fear that someone may harbor ambitions and a claimant may say, 'I am more deserving,' but Allah and the believers will accept none but Abu Bakr."
قال لي رسول الله ﷺ في مرضه: ادعي لي أبا بكر وأخاك حتى أكتب كتابا، فإني أخاف أن يتمنى متمن، ويقول قائل: أنا أولى، ويأبى الله والمؤمنون إلا أبا بكر.
Muslim narrated it in the Merits of the Companions (2387), from Ubaydullah bin Saeed, from Yazid bin Harun, from Ibrahim bin Saad, from Salih bin Kaysan, from Zuhri, from Urwa, from Ayesha, who said, and then mentioned it.Bukhari narrated it in the Rulings (7217), from Yahya bin Yahya, from Sulayman bin Bilal, from Yahya bin Saeed, who said, I heard Qasim bin Muhammad say, Ayesha said, "Oh, my head," and then mentioned it in a long hadith, the end of which is similar to what Muslim related.