Is it permissible for one who is praying an obligatory prayer to pray behind one who is praying a voluntary prayer?

Eid Abbasi : Is it permissible to perform an obligatory prayer behind one who is praying a voluntary prayer, such as tarawih?

The Shaykh : The answer: Yes, based on the authentic hadith of Mu'adh ibn Jabal in "Sahih al-Bukhari," in which it is stated that he used to pray the obligatory 'Isha' prayer behind the Prophet (peace and blessings be upon him), and then he would go to the mosque of his neighborhood and lead them in prayer; it was a voluntary prayer for him and an obligatory prayer for them. Therefore, the prayer of one who enters the mosque while the imam is praying tarawih is valid, provided that this person has not yet prayed the 'Isha' prayer. He must follow this imam. If he catches two rak'ahs, he stands up and completes the remaining two rak'ahs. If he does not catch them, even if it is before the taslim, he should join him and then complete the four rak'ahs.