What is the ruling on one who makes a mistake in his night prayer, is then informed that he prayed three units while he thought he had prayed two, and then stands up to make the three units even and continues in his prayer?

The questioner : Peace be upon you.
May Allah forgive you, O Shaykh: A man stood up to pray at night. He prayed three units while thinking he had prayed two. Then, after another person informed him that he had prayed three, he said, “I prayed two units.” After he was certain, he said, “My intention was not for three units, but my intention was for two units.” Then he stood up and made this unit even, and then continued with the witr, and finally completed the witr at the end of the night. What is the ruling on this?

The Shaykh : No, this is not correct. We say that if he is informed that he prayed three, he only prostrates for forgetfulness, because he did not decrease; rather, he increased. This is unlike the case where he prays three while four are obligatory upon him, such as the Zuhr prayer, and then he is informed; in that case, he completes it. As for this case, it is better that he not complete it; he prostrates for forgetfulness, and that is sufficient. Yes.