وَما كانَ صَلاتُهُم عِندَ البَيتِ إِلّا مُكاءً وَتَصدِيَةً ۚ فَذوقُوا العَذابَ بِما كُنتُم تَكفُرونَ

Their prayers at the House are nothing more than whistling and clapping. So, taste the punishment for having disbelieved.