Translation by Dr. Muhammad Muhsin Khan & Dr. Taqi-ud-Din al-Hilali
So that they become ingrate for that which We have given them, and that they take their enjoyment (as a warning and a threat), but they will come to know.
Word by Word — Arabic, Transliteration & Meaning
لِيَكْفُرُوا۟liyakfurūSo that they may deny
بِمَآbimā[in] what
ءَاتَيْنَـٰهُمْātaynāhumWe have given them
وَلِيَتَمَتَّعُوا۟ ۖwaliyatamattaʿūand they may enjoy (themselves)
فَسَوْفَfasawfaBut soon
يَعْلَمُونَyaʿlamūnathey will know
Tafsir Ahsan al-Bayan — Hafiz Salahuddin Yusuf
Tafsir Ahsan al-Bayan is a well-known Quran commentary by Hafiz Salahuddin Yusuf, a renowned Salafi (Ahl al-Hadith) scholar from Pakistan. This tafsir explains the meanings of the Quran in accordance with the methodology of the Salaf (early righteous generations), relying on authentic sources and straightforward language. Due to its reliability and adherence to sound Islamic scholarship, the Saudi government publishes and distributes this tafsir among the Hujjaj (pilgrims) visiting the Haramain. The tafsir is originally written in Urdu, translated to English by tohed.com.
66-1 This "laam" is *kayy*, which is for causation. That is, after being saved, their associating partners is so that they may be ungrateful for the favor and continue to enjoy the pleasures of the world. Because if they were not ungrateful, they would remain steadfast upon sincerity and would always call upon Allah alone. Although their intention is not to disbelieve, the result of committing shirk again is disbelief nonetheless.