al-Baqara 2:6

Inna'lladhīna kafarū sawāʾun ʿalayhim a-andhartahum am lam tundhirhum lā yuʾminūn "As for those who have covered over the truth: it is the same for them whether you warn them or do not warn them, they will not believe."

There is a wide gap between the load the word carries in ordinary use and the sense of the root in Arabic, so the root must be put down first.

Root k-f-r: to cover, to close over, to hide.

Its derivatives show this plainly:

• The farmer is called kāfir in Arabic — because he covers the seed with earth. The Qurʾān makes this use itself: "Like a rain whose growth delights the tillers (kuffār)" (al-Ḥadīd 57/20). The same word, in the same sūra, in an agricultural sense.
• The night is called kāfir, because it covers everything over.
• Of one who puts on armour it is said "kafara dirʿahu" — he covered his body.
• Kaffāra is the amends that close over an offence committed.

The definition that follows from this is critical: unbelief is not not-knowing; it is covering over what one knows. Ignorance and unbelief are different things. The person the Qurʾān calls kāfir is not one who has failed to see the proof set before him but one who has chosen to cover what he saw. Indeed the Qurʾān says this outright through the mouth of Moses (Mūsā) against Pharaoh: "You have certainly come to know that no one has sent these down but the Lord of the heavens and the earth" (al-Isrāʾ 17/102).

And look at the word's opposite: in the Qurʾān what is set opposite kufr is most often not īmān but thanks ("shākiran aw kafūrā", al-Insān 76/3). Thanks is to see and acknowledge what has been given; unbelief is to cover it over. Unbelief, then, is at bottom a notion of ingratitude.

This distinction takes the word out of being a term of abuse and makes it a description of a condition. It will be used that way in this commentary.

Root n-dh-r. To warn, but specifically to give advance notice of a bad outcome. This is why the Qurʾān uses two words as a pair for the prophet: bashīr (bringer of good news) and nadhīr (warner).

From the same root comes nadhr — a vow. What the two have in common is the making binding, here and now, of something that has not yet come about.

On the face of it the sentence carries a definite ruling: "whether you warn them or do not warn them, they will not believe". To draw from this a general conclusion such as "unbelievers will never believe" runs against both history and the Qurʾān itself.

For many people who were unbelievers in the years this verse came down believed afterwards; some of the best-known names in the history of Islam were still on the other side when this verse came down. The Qurʾān also keeps the door open: "Say: O My servants who have gone beyond bounds against themselves! Do not despair of God's mercy" (al-Zumar 39/53).

Most exegetes have therefore understood the verse thus: the ruling is for a particular group who have made unbelief their trait, whose stance before the proof has become fixed; it is not a general decree of destiny for every unbeliever. Indeed the verse does not say "the unbelievers", it says "those who have covered over" — those who have performed an act.

And look at whom the verse addresses: it is said to the one giving the warning. Its function is not to issue a ruling but to set the warner at ease: your task is to convey, not to produce the outcome. The Qurʾān says this plainly elsewhere: "You cannot guide whom you love" (al-Qaṣaṣ 28/56).