سنن أبي داود

Abu Hurairah reported the Messenger of Allah (ﷺ) as saying: when the call to prayer is made; the devil turns his back and breaks wind so as not to hear the call being made; but when the call is finished, he turns round. When the second call to prayer (iqamah) is made, he turns his back, and when the second call is finished, he turns round and suggest notions in the mind of the man (at prayer) to distract his attention, saying: remember such and such, referring to something the man did not have n mind, with the result that he does not know how much he has prayed.