Tafsir of Al-Kahf 18:56

And We do not send the messengers to the nations, clothed in any state whatsoever, except in the state of being bringers of good tidings to the believers of reward, and warners to the disbelievers and the disobedient of punishment. We did not send them so that signs might be proposed to them after the appearance of miracles, nor that they should be treated in a manner unbefitting their status.

And those who disbelieve argue with falsehood by proposing such things, by questioning about the story of the People of the Cave and the like out of stubbornness, and by their saying to them, "This is but a human being like yourselves who wants to favor himself over you; if Allah had willed, He would have sent down angels," and other things besides this. The qualification of the argument as being "with falsehood" is to clarify the blameworthy nature of it, for as has passed, it is linguistically general—not specific to falsehood—so that what was mentioned might be interpreted as stripping [a quality of its opposite]. What is intended here is its linguistic meaning and whatever is applied to it terminologically that satisfies that definition.

To refute—that is, to remove and invalidate—with it—namely, the argument—the truth which the messengers, peace be upon them, brought. The root of idhad (refutation) is making something slip, and dahd is mud in which one slips. A poet said: He arrived, and the Yashkuri escaped from fear of him, And he veered away just as the camel veers away from the mud. And another said: O Abu Mundhir, you sought fulfillment and gave it away, And you veered away just as the camel veers away from the slippery ground. Its usage in the sense of removing the truth is said to be an instance of using a term coined for the sensible in the intelligible realm. It is also said that you may regard it as a comparison of their speech to repulsive mire, as Al-Khafaji said: "He came to us with the mire of his thoughts to make the feet of the guidance of proofs slip."

And they have taken My signs—which I supported the messengers with, whether in word or deed—and that which they were warned of—meaning, that which they were warned of regarding the calamities that announce punishment and torment to them, or [the act of] their warning—in mockery.

Hamzah read it as huz'an with a quiescent letter (the za) and a glottal stop. Others among the seven reciters—excluding Hafs—read it with two dammahs and a glottal stop; it is a verbal noun used as an adjective for emphasis, and it may be interpreted as that which is mocked.