What is the ruling on a person who has an obligatory prayer to perform praying behind a person who is performing a voluntary prayer?

Question : The questioner says: I entered the mosque after the congregational prayer had ended, and I found a person performing a voluntary prayer, so I joined him in the prayer. After he finished, I completed what remained for me. Then, after I finished, a group of worshippers came and prayed that obligatory prayer. Is it obligatory for me to repeat the prayer, or is the first prayer sufficient?

Answer : It is not obligatory for you to repeat the prayer; rather, you are sufficient with the first prayer, because you have performed the obligatory prayer. When a person performs the obligatory prayer in the prescribed manner, he is not required to perform it a second time. However, some scholars say that it is not permissible for a person who has an obligatory prayer to perform to pray behind a person who is performing a voluntary prayer, because the obligatory prayer is more emphasized than the voluntary prayer, so it is not appropriate for someone whose prayer is more emphasized to be behind someone whose prayer is less emphasized. But the correct view is that it is permissible for a person who has an obligatory prayer to perform to pray behind a person who is performing a voluntary prayer. And the prayer of 'Isha', so when he finished, he went to his people and prayed with them the same prayer. If this had been a forbidden act, Allah would not have approved it, because Allah the Exalted does not approve anyone of an error during the time of revelation. So the correct view in this issue is that it is permissible for a person who has an obligatory prayer to perform to pray behind a person who is performing a voluntary prayer.