Adding a rak'ah to the prayer without intention; what is the ruling on his prayer?

Question:
Peace be upon you. The listener is Boulgithi Roshida from Algeria. She sent three questions, and in the first she asks: What is required of a person who commits an error in the prayer without intention? The Zuhr prayer is four rak'ahs, and he prayed five rak'ahs. What is required of him to do?

Answer:
If one adds something to the prayer that is of the same kind as it, such as adding a fifth rak'ah to a four-rak'ah prayer while in a state of forgetfulness, then his prayer is valid, but he must perform the prostration for forgetfulness for this addition. He must perform the prostration for forgetfulness for this addition, as the Prophet (peace and blessings be upon him) commanded this and did it himself (peace and blessings be upon him). Yes.