It wasnarrated that 'Abdullah said:
"The Messenger of Allah (ﷺ)said:'If anyone of you is uncertain about his prayer, let him try todowhat is correct then let him prostrate twice.'"Tanafisi said: "This is the basic rule, and no one is able to reject it." (RU)
English reference (RU): Vol. 1, Book 5, Hadith 1212 (RU)
Arabic reference (RU): Book 5, Hadith 1269 (RU)