Tafsir of Ash-Shura 42:8

"And if Allah willed, He would have made them one nation"—that is, in this world—"one nation," being guided or astray. This is an elaboration of what Ibn Abbas summarized in his statement: "upon one religion." The meaning of His saying, "But He admits whom He wills into His mercy," is that He, Exalted is He, admits into His mercy whom He wills to admit, and admits into His punishment whom He wills to admit. There is no doubt that His, the Exalted’s, will for both admissions is dependent upon the worthiness of each of the two groups to enter what they were admitted into. By necessity, the difference between mercy and punishment dictates a definitive difference in the condition of those who enter them. Thus, He did not will to make them all one nation; rather, He made them two groups. It is for this reason that it is said: "And the wrongdoers have no protector and no helper."

The apparent structure would have been to say, "And He admits whom He wills into His punishment and vengeance," to signal that the admission into punishment is on account of the individuals themselves, by virtue of their own poor choice, and not from His side, Exalted is He, as is the case with admission into mercy. Al-Zamakhshari chose the interpretation that "one nation" means "all believers," which is what Muqatil said: "upon the religion of Islam," as in His saying, "And if Allah willed, He could have gathered them upon guidance," and His saying, "And if We had willed, We could have given every soul its guidance." The meaning is: if Allah had willed—with a will of power—He would have compelled them to believe, but He, Glorified is He, willed with a will of wisdom and charged them, basing their affair upon what they choose, in order to admit the believers into His mercy—who are those intended by His saying, "whom He wills"—and to leave the wrongdoers without a protector or helper. This discourse is connected to His saying, "And those who take as allies other than Him—Allah is Guardian over them, and you, [O Muhammad], are not a manager over them," serving as an explanation for the prohibition against the intensity of his (peace be upon him) eagerness for their faith. The term "the wrongdoers" is a manifest noun substituted in place of the pronoun of those who "take [others as allies]" to indicate that their wrongdoing is the cause for what follows. Or, it is for the generic category and encompasses them primarily. He refrained from the apparent phrasing in favor of the noble structure, as the context is one of warning, and this is more effective in terrifying them, for it intimates that their being in the punishment is a matter from which there is no escape. The discussion concerns whether, after its certainty, there is anyone to save them by warding it off or removing it. Once this is negated, it is known that they are in a punishment from which there is no salvation.

This was challenged by the argument that the assumption of a "making" for all as believers is rejected by the opening of the contrast with "admitting some into His mercy," for if that were the case, all would be entering it. Thus, it would have been more appropriate to open it by "extracting some from among them and admitting them into His punishment." Perhaps it may be said: since the verse is related to what you have heard, the meaning is: "If Allah had willed, He would have made everyone a believer," as you desire and strive for. But He, Glorified is He, did not will that; rather, He made some of them believers as you desired, and made others—namely those who take allies other than Him—disbelievers, as there is no salvation for them from the punishment, as wisdom dictates. The opening with what it began is appropriate, as is not hidden from one who has a taste for the styles of discourse. However, the apparent phrasing, according to this, would be "He admits whom He wills," but it was shifted from that to this to recount a past state.

The Sheikh al-Islam said: "What the precedent of the noble structure and its context requires is that 'unity' in disbelief is intended, as in His saying, 'Mankind was one nation, then Allah sent the prophets'—the verse, according to one of the two perspectives. The meaning is: if Allah had willed, He would have made them one nation and united them upon disbelief by not sending a messenger to them to warn them of what was mentioned regarding the Day of Gathering and the various terrors within it, so they would remain as they are in disbelief. But He admits whom He wills into His mercy—meaning, it is His, Exalted is His majesty, affair to do that. Thus, He sends to everyone one who warns them of what was mentioned, and some are affected by the warning and turn their choice toward the Truth, so Allah grants them success for faith and acts of obedience and admits them into His mercy. Others are not affected by it and persist—and they are the wrongdoers—remaining in the world as they are in disbelief and ending up in the Hereafter in the Blaze, with no protector to oversee their affair and no helper to save them from the punishment." End quote.

It is not hidden that there is a type of contradiction between His saying, "Mankind was one nation," and His saying, "And if Allah willed, He would have made them one nation," according to the meaning he chose here for both. So contemplate all of that, and Allah, the Exalted, is the Granter of success.