Musnad Ahmad 30:3133

Surayj narrated to us, he said: Fulayh narrated to us, from Salamah ibn Safwan ibn Salamah al-Zuraqi, from Abu Salamah, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, when the Shaytan hears the call (Adhan), he turns away, having a sound of passing wind. When the Mu'adhdhin falls silent, he returns until he passes between a man and his heart to make him forget his prayer. So if one of you is in doubt during his prayer, let him perform the Taslim, then let him prostrate two prostrations while he is sitting."