Sunan an-Nasa'i, 1238

Rapporté par Abu Sa‘id : Le Prophète (ﷺ) a dit : "Si l’un de vous n’est pas sûr de sa prière, qu’il oublie ce dont il doute et qu’il termine sa prière en se basant sur ce dont il est certain. Quand il est sûr d’avoir terminé, qu’il se prosterne deux fois en étant assis. Si finalement il a prié cinq rak‘a, ces deux prosternations rendront sa prière paire, et s’il en a prié quatre, elles contrarieront et humilieront le diable

It was narrated from Abu Sa'eed that:The Prophet (ﷺ) said: "If one of you is not sure about his prayer, let him forget about what he is unsure of and complete his prayer on the basis of what he is sure of. When he is sure that he has completed it, let him prostrate twice while he is sitting. Then if he has 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 shaitan