Tafsir of Al-Baqarah 2:166

(When those who were followed disown) is a substitute (badal) for (when they see), in any case. It is permissible for the answer [to the oath or condition] and its attachments to intervene between the substitute and that for which it is substituted (mubdal minhu) due to the length of the substitute. It has been permitted for it to be an adverbial modifier (zarf) for (severe punishment) or an object [of a verb] not explicitly mentioned. Some have claimed that it is a substitute for the object of (you see) in the reading of the second-person singular (ta-ra), just as (when they see) is also a substitute for it.

(And that power) is in the position of a substitute of inclusion (badal al-ishtimal) for (the punishment). It is not hidden that this necessitates the permissibility of multiple substitutes, which has not been encountered in any of the grammar books. Furthermore, it is countered that in a substitute of inclusion, the mubdal minhu must logically necessitate the substitute and indicate it in summary, and the substitute must contain a pronoun referring back to the mubdal minhu; both conditions are absent here.

The meaning is: (When those who were followed)—the leaders—(disown those who followed)—i.e., their subordinates—by saying: "We disown them before You; they were not worshipping us." Mujahid read the first [verb] as active and the second as passive, meaning: the followers disowned and separated themselves from their leaders and regretted their worship.

(And they see the punishment) is a circumstantial clause (hal) for both the followers and the followed, just as in [the expression] "I met him while we were both riding," meaning: while they were seeing it. Thus, the waw is for the state (hal), and (qad) is implied. It is also said that it is a conjunction to (disown), but the drawback here is that it leads to substituting (when they see the punishment) for (when they see the punishment), which provides little benefit because, even though the subjects of the two verbs are different, the terrifying nature of the time is considered based on what occurred within it—which is the seeing of the punishment. Moreover, what is truly worthy of horror is their disowning while seeing the punishment, not the mere occurrence of it. It has been answered that the substitute is the time added to both matters, while the mubdal minhu is the time added to only one, which is the seeing. The weakness in this is that it does not remove the awkwardness, for after terrifying the time by adding it to the seeing of the punishment, there is no need to combine it with the disowning, unlike when it is made a circumstantial clause, for then the substitute is the disowning that occurs at the time of seeing the punishment.

(And all ties were severed from them): This is either a conjunction to (disown) or (they saw), or it is a circumstantial clause. The first is preferred because the basis for the waw is conjunction, and in the sentence, it maintains independence, and because it serves to increase the reasons for terror and horror without the need to estimate (qad). The ba in (from them) is for causality (sababiyyah), meaning: (were severed) due to their disbelief, (the ties) from which they used to hope for salvation. It is said [it is] for association (mulabasah), meaning: the ties were severed while connected (to them), like your saying, "Zayd went out with his garments." It is also said it is in the meaning of "from" ('an), or for transitivity, meaning: the ties severed them, just as you say, "The road separated them," from which is His saying: (so it separates you from His way).

The root of sabab (cause/tie) is a rope in general, or the rope used to reach water, or the rope one end of which is attached to a ceiling, or the rope used to climb palm trees. The intended meaning of (the ties) here are the connections that existed between the followers and the followed in the worldly life, in terms of lineage, affinities, agreement on religion, following, and being followed. It has been read as (were severed) in the passive voice; taqatta'a comes as both intransitive and transitive.