English translation
1240. It was narrated from Abū Sa'eed Al-Khudrī that the Prophet ﷺ said: "If one of you does not know whether he prayed three or four (Rak'ahs), let him pray a Rak'ah then prostrate twice after that when he is sitting. Then if he prayed five (Rak'ahs), they (the two prostrations) will make his prayer even-numbered, and if he had prayed four, they will annoy and humiliate the Shaitān." (Sahīh)
