﴿ يَوْمَ تَمُورُ ٱلسَّمَآءُ مَوْرًۭا ﴾

“[It will come to pass] on the Day when the skies will be convulsed in [a great] convulsion,”

On the day yawma is operated by la-wāqi‘un ‘will assuredly take place’ when the heaven will heave with a great heaving when it will move and spin