Waquli alhaqqu min rabbikum faman shaa falyu'min waman shaa falyakfur inna aAAtadna (surah Kahf: 29)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(18:29) Proclaim, "This is the Truth from your Lord: now whosoever will, he may accept it and whosoever will, he may reject it".  *31 (As for those who reject this,) We have prepared for such workers of iniquity a fire whose flames have encircled them.  *32 If they will ask for water there, they will be treated with such a drink as will have its residue like that of oil  *33 and burn their lips: what an evil drink and what an evil abode!

Wa qulil haqqu mir Rabbikum faman shaaa`a falyu minw wa man shaaa`a falyakfur; innaaa a`tadnaa lizzaalimeena Naaran ahaata bihim suraadiquhaa; wa iny yastagheesoo yaghaasoo bimaaa`in kalmuhli yashwil wujooh` bi`sash-sharaab; wa saaa`at murtafaqaa

*31) This verse makes it quite plain that the story of the Sleepers of the Cave has been related to tell the opponents of Islam: "This is the Truth from your Lord: now whosoever wills, he may accept it and whosoever wills, he may reject it. But people must understand that no compromise will be made in regard to the Truth just as the Sleepers of the Cave did not make any compromise with regard to their creed. They did not make any compromise in regard to the Doctrine of Tauhid after they had believed in it and categorically declared, "Our Lord is the One Who alone is the Lord of the heavens and the earth." After this declaration they did not in any way accede to the making of any compromise with their people, who had gone astray, but firmly declared, "We will not give Him up and pray to other deities, because it will be the most improper thing, if we do so." After making this declaration they left their people and deities and took refuge in the Cave without taking any provisions with them. After' this when they rose up, the only thing about which they showed any anxiety, was that their people might not succeed in forcing them back to their own faith. After relating these things, the Qur'an addresses the Holy Prophet to the effect (though these words are really meant for the opponents of Islam): "It is absolutely out of question whether any compromise can be made with mushriks and disbelievers. present the truth intact to them whether they accept it or not. If they do not accept it, they themselves will meet with an evil end. As regards those, who have accepted the Truth (whether they be youngsters or poor, indigent people or slaves or labourers,) they are really those people who have a worth with Allah, and they alone will be honoured. Therefore you should not discard them and prefer the chiefs and the rich people who may be neglectful of Allah and be slaves of their lust, even though they might be possessors of worldly grandeur. "
*32) The Arabic word ~l~ir' (Suradiq) literally means sides of a tent but, as used in the case of Hell, it may mean its external boundaries to which its flames and heat may reach. According to some commentators, it applies to the future reuse ".... its flames will encircle them" so as to refer to the flames of Hell in the Hereafter. But we are of the opinion that its flames have already encircled, in this very world, these workers of iniquity, who have turned away from the Truth and that they cannot escape them.
*33) The Arabic word ,}~ (muhl) has several lexical meanings. According to some people, it means "the residue of oil"; according to others, "lava", which is formed by the melting of things in the earth; according to some, "molten matter" and according to others "pus and blood"