Al-Kahf 18:22

They will say, that is, [some of] those disputing the number of the youths [of the cave] at the time of the Prophet (s), in other words, some of these will say that they [the youths] were: ‘Three; their dog the fourth of them’; and they, some [others] among them, will say, ‘Five; their dog the sixth of them’ — both of these sayings were those of the Christians of Najrān — guessing at random, in other words, out of supposition, not having been present with them [at the time], and this [statement ‘guessing at random’] refers back to both sayings, and is in the accusative because it is an object denoting reason, in other words, [they said this] for the reason that they were [merely] supposing it. And they, that is, the believers, will say, ‘Seven; and their dog the eighth of them’ (the sentence is [part of] the subject clause, the predicate of which is the adjectival qualification of sab‘a, ‘seven’ [namely, thāminuhum, ‘the eighth of them’] with the additional wāw [wa-thāminuhum], which is said to be for emphasis, or an indication that the adjective is [semantically] attached to that which it is qualifying). The qualification of the first two sayings as being ‘random’, but not the third, is proof that [the latter] is the satisfactory and correct [number]. Say: ‘My Lord knows best their number, and none knows them except a few’: Ibn ‘Abbās said, ‘I am [one] of these “few” [described]’, and he mentioned that they were seven. So do not contend concerning them except with an outward manner [of contention], [except] with that which has been revealed to you, and do not question concerning them, do not ask for opinions [from], any of them, [from] the People of the Scripture, the Jews. The people of Mecca asked him [the Prophet] about the story of the People of the Cave, and so he said to them, ‘I will tell you about it tomorrow’, but without adding [the words], ‘If God wills’ (inshā’a’ Llāhu) and so the following was revealed: