There was a quarrel among the tribe of Banu Amr bin Awf. News of it reached the Prophet ﷺ, so he went to them after the noon prayer to make peace between them. He said to Bilal, "If the time for the afternoon prayer comes and I have not yet returned, tell Abu Bakr to lead the people in prayer." The hadith continues at length.
كان قتال بين بني عمرو بن عوف، فبلغ ذلك النبي ﷺ فأتاهم ليصلح بينهم بعد الظهر، فقال لبلال: إن حضرت صلاة العصر ولم آتك فمر أبا بكر فليصل بالناس… الحديث بطوله.
Abu Dawud (941), Nasai (793), and Ahmad (22816) all narrated it, and Ibn Khuzayma (853) and Ibn Hibban (2261) graded it sahih, all of them through the route of Hammad bin Zayd, who said, "Abu Hazim narrated to us, from Sahl bin Saad," and he related it. Its chain of transmission is sahih.The hadith concerns the story of Abu Bakr leading the Asr prayer when the Prophet ﷺ was absent. Bukhari narrated it in the Book of Rulings (7190) through the route of Hammad bin Zayd, from Abu Hazim, with the same wording. Muslim narrated it in the Book of Prayer (421) through other routes from Abu Hazim with the same wording, but neither of them includes the point being cited here, which is his statement, "If the time for Asr prayer comes and I have not returned to you, tell Abu Bakr to lead the people in prayer."It has also been narrated from Ayesha that she said, the Messenger of Allah ﷺ said, "It is not fitting for a people who have Abu Bakr among them that anyone other than him should lead them in prayer." Tirmidhi narrated it (3673) from Nasr bin Abdul-Rahman Kufi, who said, "Ahmad bin Bashir narrated to us, from Isa bin Maymun Ansari, from Qasim bin Muhammad, from Ayesha," and he related it. He said, "This is a gharib hadith." And it is as he said, for Isa bin Maymun Ansari is considered daif by the majority of scholars.