This because they contended against Allah and His Messenger: If any contend against Allah and His Messenger, Allah is strict in punishment. (13)
Tafsir
At the time of confrontation what is required of the people of Truth is steadfastness. They should not be disheartened under any circumstances. The gift readily given by God in return for this steadfastness is the striking of terror into the hearts of the enemies of Truth, and nothing can save from defeat any such group as is terror-stricken by its opponents.
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