ثُمَّ بَدَا لَهُم مِّنۢ بَعْدِ مَا رَأَوُا۟ ٱلْءَايَٰتِ لَيَسْجُنُنَّهُۥ حَتَّىٰ حِينٍ
The root ب-د-و: to come out into the open, to appear. The subject of the verb is not stated: "[something] appeared to them". In Arabic this is a usage that leaves the agent indeterminate.
And the word order of the sentence must be recorded, because it lodges the contradiction inside the sentence:
| Element | Expression |
|---|---|
| The outcome | La-yasjununnahu ḥattā ḥīn — prison |
| The clause put in place of a ground | Min baʿdi mā raʾawu'l-āyāt — after they had seen the proofs |
I record this as my own reading, and its ground is the adverbial clause: the verse says that the decision was taken despite the proofs. That is, the decision does not arise from a lack of knowledge.
And this is the continuation of the command aʿriḍ ʿan hādhā ("let this be") in verse 29: shutting the affair was not enough, and its source was removed as well.
This indefiniteness accords with the axis of al-Kahf — there too, in all four stories, the duration was unknown. The same here: the length of the stay in prison is not measured in the text. Indeed in verse 42 only biḍʿa sinīn will be said: "a few years".