The imam prayed one rak'ah in tarawih by mistake, then said the taslim, and then completed it with another rak'ah to make it an even number. What is the ruling on his action?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: The imam prayed tarawih, and after he had prayed eight rak'ahs, he stood up and prayed one rak'ah by mistake. Then he prayed another rak'ah after that to break up this odd number, so that the last of his night prayer would be an odd number. Thus, the total became ten rak'ahs. Then he came with the witr rak'ah after that and completed eleven rak'ahs. What is the ruling on this action of his?

Answer:
Yes. If he prayed the ninth rak'ah, and then he remembered or recalled it, and stood up and completed the two rak'ahs, he should add a rak'ah to the one before it to make it two, and then he should pray witr with one rak'ah. There is no harm in that. Yes. But he should perform sujud al-sahw (the prostration for forgetfulness). He should perform sujud al-sahw. Yes.