Sahih Bukhari Volume 002, Book 022, Hadith Number 326.
Narated By Sahl bin Sad As-Sa'idiÂ : The news about the differences amongst the people of Bani'Amr bin 'Auf reached Allah's Apostle and so he went to them along with some of his companions to affect a reconciliation between them. Allah's Apostle was delayed there, and the time of the prayer was due. Bilal went to Abu Bakr and said to him, "Allah's Apostle has been delayed (there) and the time of prayer is due. So will you lead the people in prayer?" Abu Bakr said, "Yes, if you wish." Bilal pronounced the Iqama and Abu Bakr, went forward and said Takbir for the people. In the mean-time Allah's Apostle came crossing the rows (of the praying people) and stood in the (first) row and the people started clapping. Abu Bakr, would never glance side-ways in his prayer but when the people clapped much he looked back and (saw) Allah's Apostle. Allah's Apostle beckoned him to carry on the prayer. Abu Bakr raised his hands and thanked Allah, and retreated till he reached the (first) row. Allah's Apostle went forward and led the people in the prayer. When he completed the prayer he faced the people and said, "O people! Why did you start clapping when something unusual happened to you in the prayer? Clapping is only for women. So whoever amongst you comes across something in the prayer should say, 'Subhan-Allah' for there is none who will not turn round on hearing him saying Subhan-Allah. O Ab-u Bakr! What prevented you from leading the people in the prayer when I beckoned you to do so?" Abu Bakr replied, "How dare the son of Abu Quhafa lead the prayer in the presence of Allah's Apostle ?"