(Or that you say) is conjoined to (that you say). Both are read with the ya (third-person prefix) as an iltifat (shift in mode of address) from the second-person address in "follow it and fear [Allah]." The subsequent address is also an iltifat, and its significance is not hidden. Al-Qutb said: The Almighty addressed them first as He did, then when He reached the narration of their base statements, He turned away from them and shifted to the third person as if they were absent. Then, when the Almighty intended to rebuke them afterwards, He addressed them again. This is an iltifat of the utmost excellence.
(If the Book had been sent down to us) just as it was sent down to them, (we would have been better guided than them) to the truth, which is the ultimate goal, or to the rulings and laws it contains, because our minds are more acute and our understanding more penetrating.
(So there has come to you) is related to an elided [verb] indicated by the fa of eloquence (al-fa' al-fasihah), which is either the cause or the condition for it; meaning: do not offer such excuses, for there has come to you, etc., or: if you are truthful in what you claim about yourselves—that had the Book been sent down to you [you would have been better guided]—then what you supposed has occurred, and there has come to you (a clear proof), a proof of exalted status, manifest, which you recognize due to its clarity and because it is in your own tongue, (from your Lord). The prepositional phrase relates to an elided [word] that serves as an adjective to "a clear proof," and it is also valid for it to relate to "has come to you." In any case, it indicates its relative merit while pointing to its intrinsic nobility. Mentioning the attribute of Lordship while adding it to their pronoun contains a subtle emphasis on the obligation of obedience.
(And guidance and mercy) are conjoined to (clear proof). Their indefinite status is for the purpose of exaltation. The meaning of all this is the Quran. It is described first as a "clear proof" to signify their complete ability to study it, and secondly as "guidance and mercy" to alert [the reader] that it contains what the Torah contained of guiding and showing mercy to people; indeed, it is the essence of guidance and mercy itself. In Al-Tafsir Al-Kabir, it is stated: If it is said, "The clear proof, the guidance, and the mercy are one, so what is the benefit of the repetition?" We answer: The Quran is a "clear proof" regarding what is known through audition, and it is "guidance" regarding what is known through audition and reason. Since the benefit differs, this conjunction is valid. The subtlety here is not hidden.
(Who is more unjust than one who denies the verses of Allah) The fa is for ordering what follows it upon what precedes it, for the arrival of the Quran—described as it has been—necessitates the extreme injustice of those who deny it. The intent of the relative pronoun is those addressed [previously]. It is placed in the position of their pronoun by way of iltifat to explicitly state their possession of the attribute contained in the relative clause, to signal the cause of the ruling, and to demote them from the rank of direct address. What came to them is expressed as "verses of Allah" to emphasize the gravity of the matter. It is also read kadhdhaba (with no tashdid on the dhal). The first prepositional phrase is related to what is with it, and the second is likely related to that as well, which is the most apparent. It is also possible that it relates to an elided word acting as a state (hal), meaning: he denies it while the verses of Allah are with him.
(And turns away from them) i.e., avoids them without reflecting upon them, as has been narrated from Ibn Abbas, Mujahid, and others; or, turns people away from them—thus combining misguidance and leading others astray. The verb, according to the first interpretation, is intransitive, and according to the second, it is transitive, which is the most common usage.
(We will punish those who turn away from Our verses) is a threat to them, clarifying the penalty for their turning away or their obstructing others, such that the penalty for their denial is understood from it. The relative pronoun is placed in the position of the pronoun to establish the basis for the punishment: (with the worst of punishment) i.e., the intense, evil punishment, (because of what they used to turn away) i.e., because of what they used to do of turning away, signifying renewal and continuity. This is an explicit statement of what was implied by applying the ruling to the relative pronoun—namely, the causality of what is in the relative clause.
