He asked Abu Saeed Khudri, "One of us prays and does not know how much he has prayed."Abu Saeed replied, the Messenger of Allah ﷺ said, "When one of you prays and does not know how much he has prayed, let him perform two prostrations. If Satan comes to him and says, 'You have broken your wudu,' let him say, 'You lie,' unless he detects a smell with his nose or hears a sound with his ear."
حدثنا يحيى عن هشام عن يحيى
أنه سأل أبا سعيد الخدري قال أحدنا يصلي لا يدري كم صلى قال قال رسول الله ﷺ إذا صلى أحدكم فلم يدر كم صلى فليسجد سجدتين فإن أتاه الشيطان فقال إنك قد أحدثت فليقل كذبت إلا ما وجد ريحا بأنفه أو صوتا بأذنه