Q: What is the duty of a person who forgets to perform a rak‘ah of his prayer and then remembers it in the last rak‘ah? For example, thinking first rak‘ah of his prayer to be the second one, he performs the third and the fourth rak‘ah; then in this last rak‘ah he realizes that it is really only the third rak‘ah. What should he do?
A: It is obligatory for him before reciting the final salām of the prayer to perform the rak‘ah he has missed and then recites the salām. As he had not done an obligatory tashahhud in its proper place, it will be obligatory for him, based on a caution, to perform its qaḍā’ and two prostrations of inadvertence.