Tafsir of Yunus 10:40

And of them are those who believe in it: This is a description of their state after the expected interpretation has come, as it has been said, since at that time it becomes possible to categorize them into those who believe in it and those who do not believe in it, due to the necessity of the impossibility of believing in something without having knowledge of it, and because all of them shared in the act of denial prior to that; thus, the pronoun refers to the deniers.

The meaning of believing in it is either merely believing in its truthfulness—that is, among them are those who attest to it within themselves that it is the truth upon encompassing its knowledge and the arrival of its interpretation, yet they remain obstinate and arrogant—or it refers to true belief, meaning among them are those who will believe in it and repent from disbelief.

And of them are those who do not believe in it: That is, they do not attest to it within themselves, just as they do not attest to it outwardly, due to their extreme stupidity which prevents them from encompassing its knowledge as is proper, or due to the feebleness of their intellect and the impairment of their discernment, and their inability to extract their knowledge from the contradiction of the conjectures and delusions to which they have become accustomed. Consequently, they remain in the state of doubt they were previously in, or they do not believe in it in what is to come, but rather die in their state of disbelief, whether they were obstinate or doubtful.