Musnad Abu Ya'la al-Mawsili 252:8

Ishaq narrated to us, Sufyan narrated to us, from Abu Hazim, who heard it from Sahl ibn Sa’d—and he is one of the companions of the Prophet, may Allah bless him and grant him peace—who said: Words occurred between the Aws and the Khazraj until they reached out to one another. The Messenger of Allah, may Allah bless him and grant him peace, was approached and informed. He came to them, and Bilal gave the call to prayer. The Messenger of Allah, may Allah bless him and grant him peace, was delayed. When he was delayed, [Bilal] established the prayer, and Abu Bakr stepped forward to lead the people in prayer. The Messenger of Allah, may Allah bless him and grant him peace, came from that arrival of his and passed through the people until he reached the row that was behind Abu Bakr. The people clapped, and Abu Bakr would not turn around in the prayer. When he heard the clapping, he turned around, and behold, it was the Messenger of Allah, may Allah bless him and grant him peace. The Prophet, may Allah bless him and grant him peace, signaled to him to remain. He [Abu Bakr] said, "It is not for the son of Abu Quhafa to stand in front of the Messenger of Allah, may Allah bless him and grant him peace." He [the Prophet] said to the people, "What is the matter with you that when something happens to you in your prayer, you clap? It is only for women. Whoever experiences something in his prayer, let him say: 'Subhan Allah.'"