Tafsir of An-Nahl 16:55

(That they may deny what We have given them) of the blessing of relief from [affliction]. Kufr here means showing ingratitude for the blessing. The lam is the lam of consequence and ultimate outcome, and it is a metaphorical dependency; for since their disbelief and polytheism resulted in nothing but the rejection of what Allah the Exalted had bestowed upon them, it was treated as if it were the intended final cause for it. It is also permissible that kufr means denial—that is, denying that this blessing came from Allah the Exalted—and the lam is the same as before; the two meanings are close.

(So enjoy) This is a command of threat, as is one of the metaphorical meanings of the command according to the majority, just as a master might say to his slave, "Do what you will." The shift to direct address (the second person) is to signal the extremity of the indignation.

Abu al-‘Aliyah read it as (fayatamatta‘u), with the ya prefixed, the mim quiescent, and the ta vowelled with a fatha; it is the imperfect tense of ta-ma-ta-‘a, lightened and built in the passive voice. This has been narrated by Makhul al-Shami from Abu Rafi‘, the freed slave of the Prophet (may Allah exalt him and grant him peace). It is linked to (li-yakfuru), on the basis that both commands are presented to them in light of their polytheism. It is also possible that the lam in (li-yakfuru) is the lam of command, and the intent behind it is to threaten them by leaving them to what they are in, due to their being forsaken. In this case, the fa is the fa occurring in the response to the command, and what follows it is in the accusative case by the omission of the nun. It is also permissible to consider it jussive by conjunction, just as it is conjugated in the accusative by conjunction if the lam is the prepositional lam.

(Then you shall soon know) the consequence of your affair and the punishment that will descend upon you. There is a severe warning in this, as the object is not mentioned, signifying that it is beyond description. Abu al-‘Aliyah also read it as (ya‘lamun) with the ya prefixed, and this was also narrated by Makhul from Abu Rafi‘.