Thou wouldst have thought them awake, as they lay sleeping, while We turned them now to the right, now to the left,' and their dog 'stretching its paws on the threshold. Hadst thou observed them surely thou wouldst have turned thy back on them in flight, and been filled with terror of them. 18 And thus did We rouse them that they might question each other. A speaker among them said: How long have you tarried? They said: We have tarried for a day or a part of a day. (Others) said: Your Lord knows best how long you have tarried. Now send one of you with this silver (coin) of yours to the city, then let him see which of them has purest food, so let him bring you provision from it, and let him behave with gentleness, and by no means make your case known to any one: 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 even so We made them stumble upon them, that they might know that God's promise is true, and that the Hour -- there is no doubt of it. When they were contending among themselves of their affair then they said, 'Build over them a building; their Lord knows of them very well.' Said those who prevailed over their affair, 'We will raise over them a place of worship.' 21 Anon they will say: they were three the fourth of them their dog. And they will say: they were five, the sixth of them their dog - guessing at the unknown - and they will say: they were seven, the eighth of them their dog. Say thou: my Lord is the Best Knower of their number; there knew them only a few; so debate thou not regarding them except an outward debating, and ask not regarding them anyone of them. 22