Hadith 1662
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) said: "When the muezzin gives the call to prayer (adhan), Satan turns his back and goes away, passing wind. When the muezzin becomes silent, he returns. Then when the muezzin gives the iqamah, he again turns his back and goes away, passing wind. When the muezzin becomes silent, Satan comes back and begins to cast different thoughts into a person's heart, to the extent that a person does not even remember how many units of prayer he has performed. When someone faces such a situation while praying, he should perform two prostrations of forgetfulness (sajda sahw) during the sitting (qa'dah)."