Tafsir of Az-Zumar 39:4

(If Allah had intended to take a son, He would have chosen from what He creates what He wills.) This is an initiation (isti’naf) directed toward establishing the truth and invalidating the claim that the angels are the daughters of Allah and that ‘Isa (Jesus) is His son—exalted is Allah far above that—by declaring the absolute impossibility of taking a son in relation to Him, the Exalted. Through this, the impossibility of what was claimed is subsumed as a primary necessity. The essence of the meaning is: If Allah, the Exalted, had intended to take a son, that intention would have been impossible because it would relate to an impossibility, namely, the act of "taking" (ittikhadh). However, it is not permissible for the Creator to intend an impossibility, because doing so would imply favoring one possibility over another.

The core of the argument is: "If He were to take a son, it would be impossible, for it would necessitate what contradicts Divinity." The discourse was adjusted to: "If He had intended to take a son, it would be impossible for Him to will it," in order to be more hyperbolic. Then, this response was elided, and "He would have chosen..." was brought in its place to alert [the reader] that this possibility [of choosing] exists, unlike the first [the taking of a son]. If the act of "taking a son" were something possible, it would have been permissible for Him—exalted is His majesty above that. Thus, the logical consequence (lazim) is negated, and the antecedent (malzum) is established without difficulty.

It is also possible that the meaning is: "If Allah had intended to take [a son], it would be impossible and invalid." However, this is based on the intent of negating the validity of both conditions—the intention and its absence—akin to the saying, "If he did not fear Allah, he would not have disobeyed Him," where the second is not negated by the first, and there is no need to explain the entailment. If that is impossible, then "choosing" (istifa') is possible, and He, the Glorified, has indeed chosen from His creatures whomever He willed, such as the angels and ‘Isa. It should not escape you that choosing is not the same as taking a son. The response in this interpretation is also elided, replaced by that which conveys greater emphasis. The reason "He would have chosen" was not made the direct response is that the meaning would then become: "If He intended to take a son, He would have chosen [one] by way of analogy." In that case, proving the choice would be the goal of the statement, just as seeking praise through the negation of disobedience is the goal in the example of the door, and that is not the subject of the discussion here. Under both interpretations, it is of the style of [the poem]: "There is no fault in them, except that their swords have notches from clashing with the enemy."

It is also permitted that the meaning of the verse is: "If Allah, the Exalted, had intended to take a son, He would have made a creature a son," since there is no existing thing other than Him except that it is created by Him. The consequent (tali) is impossible due to the complete disparity between the created and the Creator, and the state of being a "son" contradicts that disparity; therefore, the antecedent (muqaddam) is likewise. His saying, (He would have chosen from what He creates what He wills), would then mean: "He would have taken him as a son by way of metaphor." The preceding interpretation is preferred due to the emphasis I have pointed out.

His saying, (Exalted is He), is a confirmation of what was mentioned regarding the impossibility of taking a son in relation to Him, and an emphasis on His transcendence. That is, His absolute transcendence. "Subhanahu" is a verbal noun (masdar) from sabbaha, meaning to distance or to praise—as it is a proper name for glorification spoken by the tongues of servants—or that they glorify Him with a glorification worthy of His majesty.

His saying: (He is Allah, the One, the Prevailing (al-Qahhar)) This is an initiation confirming His transcendence above that as well, for taking a son implies divisibility and the separation of one thing from another. It also implies similarity between the son and the father. The true, essential unity—which is at the highest level of the unity necessary for Him, the Exalted, by definitive rational proofs—rejects divisibility and separation explicitly, as these are properties of bodies. Since they are considered in the concept of essential unity as things to be negated, they reject the aforementioned "taking."

Likewise, [the unity] rejects similarity, whether it is interpreted as the ancient Mu'tazilah (such as al-Jubba'i, his son, and Abu Hashim) interpreted it—that is, sharing in the most specific attributes, like the sharing of Zayd and ‘Amr in "rationality"—or as the investigators of the Maturidis interpreted it—sharing in all essential attributes, like his sharing with him in "animality" and "rationality"—or as attributed to al-Ash'ari, which is the equality between two things in every aspect. Perhaps he intended something similar to what was mentioned regarding the Maturidis. If "equality in every aspect" is meant, then multiplicity is negated, and therefore similarity is negated, based on their principle that essential unity, just as it necessitates the negation of dimensional quantities, necessitates the negation of rational plurality, and that similarity necessitates multiplicity, which necessitates the existence of the aforementioned parts. This has been stated, and it contains long discussions and considerable discourse, some of which we will mention, if Allah wills, in the commentary on Surah al-Ikhlas.

Therefore, it is better to limit the discussion to the incompatibility of essential unity with divisibility and separation, as they necessitate external composition—a matter upon which philosophers and theologians are in consensus regarding its impossibility for Him, the Exalted. Its proof is too manifest to be mentioned.

Likewise, the description of "Prevailing" (al-Qahhariyyah) rejects the taking of a son. This has been argued in several ways: Some say that al-Qahhariyyah necessitates essential self-sufficiency, which is the highest level of self-sufficiency, and this necessitates abstraction from matter, whereas the birth of a son from a thing necessitates it. Others say that al-Qahhariyyah necessitates complete self-sufficiency, which necessitates complete abstraction (simplicity) in all aspects; thus, there is no genus, species, matter, form, accidents, or parts, nor anything that would detract from perfect, true simplicity. Since taking a son involves separation and similarity, it detracts from that simplicity, thus detracting from self-sufficiency, and thus detracting from al-Qahhariyyah. The Exalted has indicated that self-sufficiency is incompatible with having a son in His saying: (And they said, "The Most Merciful has taken a son." Exalted is He! Rather, He is the Self-Sufficient.)

It is also said that taking a son necessitates the separation of something from Him, which would mean He is affected and "overpowered" (maqhur), not the "effector" or "prevailing" (qahhar). Exalted is He far above that! Since He is, in His majesty, al-Qahhar—as is the requirement of Divinity—it is impossible for Him to have a son.

It is also said that al-Qahhariyyah is incompatible with cessation/decease, for if the Qahhar were to be subject to it, He would be maqhur (overpowered) by the remover. Hence, it is said that He is Subhanahu (the One) who overpowers His servants through death. One of the greatest benefits of a son to them is that he stands in the place of the father after his cessation. If there is no cessation, there is no need for a son. This, while being a rhetorical argument, is not without debate, as is evident.

Al-Zamakhshari connected His saying, (Exalted is He, He is Allah...), etc., to His saying, (And those who took as allies others besides Him...), etc., as a confirmation of the negation of Him having an ally and the negation of Him having a son. Perhaps the explanation for this is clear, so reflect upon it.