Sayyiduna Sahl bin Sa’d (may Allah be pleased with him) narrates: There was a dispute among the Banu Amr bin Awf tribe. When the Prophet Muhammad (peace and blessings be upon him) received this news, he went to them after the Zuhr prayer to reconcile between them and said:“Bilal, if the time for prayer comes and I do not arrive, then instruct Abu Bakr to lead the people in prayer.”When the time for Asr arrived, Sayyiduna Bilal (may Allah be pleased with him) gave the call to prayer, then the Iqamah, and instructed Sayyiduna Abu Bakr to lead the prayer. So he stepped forward (and began the prayer). Meanwhile, the Messenger of Allah (peace and blessings be upon him) also arrived. When the people saw him, they began clapping their hands. The Messenger of Allah (peace and blessings be upon him) came through the rows of people and stood behind Sayyiduna Abu Bakr (may Allah be pleased with him). Sayyiduna Abu Bakr (may Allah be pleased with him), when engaged in prayer, would not pay attention to anything else, but this time, when he thought the clapping was not stopping, he turned around and saw the Prophet Muhammad (peace and blessings be upon him) behind him. But the Prophet (peace and blessings be upon him) gestured to him to continue the prayer. Sayyiduna Abu Bakr (may Allah be pleased with him) paused for a moment, but then, praising Allah, stepped back on his heels, and the Messenger of Allah (peace and blessings be upon him) moved forward and led the people in prayer. When he (peace and blessings be upon him) completed the prayer, he said:“O Abu Bakr! When I gestured to you, what prevented you from continuing the prayer?”Sayyiduna Abu Bakr (may Allah be pleased with him) replied:“It does not befit the son of Abu Quhafa to lead the Messenger of Allah (peace and blessings be upon him) in prayer.”Then the Prophet (peace and blessings be upon him) said to the people:“If anything happens to you during prayer, men should say ‘Subhan Allah’ and women should clap their hands.”Then he (peace and blessings be upon him) said:“Well, why did you clap your hands?”They said:“We wanted to inform Abu Bakr (may Allah be pleased with him) of your arrival.”Then the Prophet (peace and blessings be upon him) said:“Clapping is for women, and saying ‘Subhan Allah’ is for men.”