Abu Bakr led the people in prayer while the Messenger of Allah ﷺ was in the row.
أخبرنا محمد بن المثنى قال حدثنا بكر بن عيسى صاحب البصرى قال سمعت شعبة يذكر عن نعيم بن أبي هند عن أبي وائل عن مسروق
أن أبا بكر صلى للناس ورسول الله ﷺ في الصف
Its isnad is sahih. Tirmidhi narrated it in the Book of Prayer, a chapter on it, no. 362, from the hadith of Shubah, through this route, and Tirmidhi said, hasan sahih ghareeb. It is also found in Al-Kubra, no. 861.