Volume 2, Book 22, Number 323:
Narrated Abu Huraira:
Allah’s Apostle said, “When the call for prayer is made, Satan takes to his heels passing wind so
that he may not hear the Adhan and when the call is finished he comes back, and when the Iqama is
pronounced, Satan again takes to his heels, and when the Iqama is finished he comes back again and
tries to interfere with the person and his thoughts and say, “Remember this and that (which he has
not thought of before the prayer)”, till the praying person forgets how much he has prayed. If anyone
of you does not remember whether he has offered three or four Rakat then he should perform two
prostrations of Sahu while sitting.