﴿ يَوْمَ نَبْطِشُ ٱلْبَطْشَةَ ٱلْكُبْرَىٰٓ إِنَّا مُنتَقِمُونَ ﴾

“on the Day when We shall seize [all sinners] with a most mighty onslaught, We shall, verily, inflict Our retribution [on you as well]!”

Mention the day when We shall assault with the most mighty assault — this was the day of the battle of Badr — then indeed We shall take vengeance on them al-batsh means ‘to seize violently’.