You might have thought them awake, though they were sleeping. We turned them about to the right and to the left, while their dog stretched its paws at the entrance. Had you seen them you would surely have become filled with terror and turned your back on them in flight. 18 And so, [in the course of time,] We awakened them; and they began to ask one another [as to what had happened to them]. One of them asked: "How long have you remained thus?" [The others] answered: "We have remained thus a day, or part of a day." Said they [who were endowed with deeper insight]: "Your Sustainer knows best how long you have thus remained. Let, then, one of you go with these silver coins to the town, and let him find out what food is purest there, and bring you thereof [some] provisions. But let him behave with great care and by no means make anyone aware of you: 19 for, behold, if they should come to know of you, they might stone you to death or force you back to their faith - in which case you would never attain to any good!" 20 And thus did We make (men) to get knowledge of them that they might know that Allah's promise is true and that as for the hour there is no doubt about it. When they disputed among themselves about their affair and said: Erect an edifice over them-- their Lord best knows them. Those who prevailed in their affair said: We will certainly raise a masjid over them. 21 (They will say, 'Three; and 'their dog was the fourth of them.' They will say, 'Five; and their dog was the sixth of them, guessing at the Unseen. They will say, 'Seven; and their dog was the eighth of them.' Say: 'My Lord knows very well their number, and none knows them, except a few.' So do not dispute with them, except in outward disputation, and ask not any of them for a pronouncement on them. 22