Question
Is it permissible for the intention of the imam to be a Sunnah, as in the Taraweeh prayer, while the follower has the obligation of the Isha prayer, or should he pray the obligation alone?
Answer
I say, and with God's help: The follower prays his obligatory prayer alone; due to the invalidity of following someone who is performing a voluntary prayer; because of the weakness of his prayer, and God knows best.