Musnad Ahmad 30:1020

The Messenger of Allah, may Allah bless him and grant him peace, said: "When the call to prayer is made, the Shaytan turns his back, passing wind so that he does not hear the call. When the call is finished, he returns. Then, when the Iqamah is called, he turns his back. When the Iqamah is finished, he returns until he inserts himself between a man and his own self, saying to him: 'Remember such-and-such, remember such-and-such,' regarding things he was not remembering before, until the man remains not knowing how he prayed."