Answered by Shaykh Faraz Rabbani
If one omits a wajib in salah on purpose?
… one has sinned, cannot perform a forgetfulness prostration, and must repent and repeat the prayer.
If one does something prohibitively disliked in salah on purpose, ???
… one has sinned, cannot perform a forgetfulness prostration, and must repent and repeat the prayer.
If one omits a wajib while praying behind the imam, one does not perform a forgetfulness prostration, but does one have to repeat the prayer????
… one has sinned (if intentional), cannot perform a forgetfulness prostration, and must repent and repeat the prayer.
If one performs something prohibitively disliked behind the imam (e.g. reciting behind him), does one have to repeat the prayer???
… one has sinned (if intentional), cannot perform a forgetfulness prostration, and must repent and repeat the prayer.
Wassalam,
Faraz.