One who joins the prayer late forgot an obligatory act: does he have to perform the prostration for forgetfulness?

Question : A man forgot to say "Subhan Rabbi al-Azim" (Glory be to my Lord, the Exalted) during the bowing, and he caught up with the imam in the second unit of prayer?

Answer : This forgetfulness requires him to perform the prostration for forgetfulness, because he left out an obligatory act. As for this follower who missed part of the prayer, when he stands up and performs the unit he missed, we say: it is obligatory for you to perform the prostration for forgetfulness for leaving out the obligatory act. Why? Because if you prostrate now, you will not be in opposition to the imam, since you have separated yourself to make up what you missed of the prayer. Is that clear? Good.