Lady Aisha Siddiqa (may Allah be pleased with her) narrates: During his illness, the Prophet Muhammad (peace be upon him) said: "Call your father Abu Bakr to me so that I may write a document, for I fear that someone else may desire (the caliphate) and may say that he is more deserving of it, although Allah Almighty and the believers will accept none but Abu Bakr (as the caliph)."
Hadith Referenceصحیح ابن حبان / كتاب التاريخ / 6597
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «تخريج فقه السيرة» (466): خ.فضيلة الشيخ العلّامة شُعيب الأرناؤوطNull