﴿ فَلَمَّا كَشَفْنَا عَنْهُمُ ٱلرِّجْزَ إِلَىٰٓ أَجَلٍ هُم بَٰلِغُوهُ إِذَا هُمْ يَنكُثُونَ ﴾

“But whenever We removed the plague from them, giving them time to make good their promise, lo, they would break their word.”

But when We removed through the supplication of Moses the terror from them to a term which they should reach lo! they were already reneging breaking their covenant and persisting in their disbelief.