Tafsir of Al-Kahf 18:91

"Thus" (كذلك): It is the predicate of an omitted subject; that is, the affair of Dhu al-Qarnayn is like that. The reference is to what was described previously regarding his reaching the setting and rising of the sun and what he did there. The benefit of this is to magnify him and his affair, or his affair among them is like his affair among the people of the West in terms of giving the choice and the decision.

It is also permissible for it to be an adjective for an omitted verbal noun (masdar) for "he found," meaning: he found it rising, a finding like his finding it setting in a murky spring. Or, it is an adjective for an omitted verbal noun for "We did not make," meaning: We did not make a covering for them, a making that is like the making which you possess regarding the bounties We have bestowed upon you of luxurious garments and elevated buildings; however, this is not immediately grasped by the understanding. Or, it is an adjective for "covering" (سترا), and the meaning regarding it is like the one preceding it, though it contains what it contains. Or, it is an adjective for "a people" (قوم), meaning: upon a people like that group upon whom the sun sets, in terms of disbelief and the ruling. Or, it is governed by "reached," meaning: he reached its setting place just as he reached its rising place.

"And We have encompassed what is with him" (وقد أحطنا بما لديه):—of soldiers, instruments, and the means of sovereignty—"in knowledge" (خبرا): a knowledge that relates to its manifest and hidden aspects.

• According to the first interpretation: This provides an increase in the magnification of the affair, indicating that it is far beyond what was described, to an extent that nothing encompasses except the knowledge of the Subtle, the All-Aware.
• According to the second: It is an interpretation of what he endured in his journey until he reached [the destination], so the meaning is: We have encompassed what he encountered and what he attained during his journey in knowledge.
• Or as an exaltation of the means that led him to it in His saying: "So he followed a means until, when he reached..."—meaning: We have encompassed the means he possessed that led him to this remote location, which others were not given. As mentioned in al-Kashf, this is more apparent than the [interpretation of] intimidation.
• According to the second [variant]: It is a completion that benefits the excellence of his choices; meaning: We have encompassed the excellence of his receptivity and the quality of his actions in knowledge.
• According to the third: It is to clarify that it is thus in the view of the eye, while in reality, no one encompasses its knowledge except Allah, Exalted is He.
• According to the fourth and fifth: It is an epilogue to the story, or to both stories, so it does not contradict them as some have imagined.
• According to the sixth: It is a completion that confirms he treated them with the same practice he used with those he found at the setting of the sun.