﴿ لِيَكْفُرُوا۟ بِمَآ ءَاتَيْنَٰهُمْ وَلِيَتَمَتَّعُوا۟ ۖ فَسَوْفَ يَعْلَمُونَ ﴾

“and thus they show utter ingratitude for all that We have vouchsafed them, and go on [thoughtlessly] enjoying their worldly life.”

that they may be ungrateful for what We have bestowed on them of graces and that they may seek enjoyment in consenting to worship idols together a variant reading for the purposive wa-li-yatamatta‘ū has wa’l-yatamatta‘ū ‘and let them seek their enjoyment’ as an imperative denoting a threat for they will soon know! the consequences of this.