Tafsir of An-Nahl 16:38-39

{And they swore by Allah their strongest oaths...} This is conjoined to the verse: {And those who associated partners said...} (An-Naḥl: 35). This serves as an indication that these are two grave acts of disbelief, both characterized and worthy of being recounted and recorded: their attribution of their sins to the will of Allah, and their denial of the Resurrection while swearing oaths upon it.

{Nay, [He will resurrect them]} This is an affirmation of what follows the negation. It means: "Nay, He will indeed resurrect them."

{A promise [which is] binding upon Him} This is a verbal noun (maṣdar) that emphasizes what is indicated by "Nay," because the act of resurrecting is a promise from Allah. It clarifies that the fulfillment of this promise is a right and an obligation upon Him according to [the requirements of] wisdom.

{But most of the people do not know} They do not know that they will be resurrected, or that it is a promise binding upon Allah. This is because they say: "Nothing is binding upon Allah—neither the reward of a doer nor any other requirement of wisdom."

{That He may make clear to them} This is linked to what is indicated by "Nay"—meaning: He will resurrect them so that He may make clear to them [the truth]. The pronoun refers to those who die, and it is general, encompassing both the believers and the disbelievers. The matter in which they differed is the truth.

{And that those who disbelieved may know that they [were liars]} They lied in their saying: {If Allah had willed, we would not have worshipped anything other than Him}, and in their saying: {Allah will not resurrect those who die}.

It has also been said: It is permissible for this to be linked to His saying: {And We certainly sent into every nation a messenger} (An-Naḥl: 36)—meaning: We sent him to make clear to them that in which they differed, and [to show] that they were in error before him, fabricating lies against Allah.

{Our word to a thing when We intend it is only that We say to it, "Be," and it is.}