18:23

(Some) say they were three, the dog being the fourth among them; (others) say they were five, the dog being the sixth,- doubtfully guessing at the unknown; (yet others) say they were seven, the dog being the eighth. Say thou: "My Lord knoweth best their number; It is but few that know their (real case)." Enter not, therefore, into controversies concerning them, except on a matter that is clear, nor consult any of them about (the affair of) the Sleepers.

Without adding, "So please Allah!" and call thy Lord to mind when thou forgettest, and say, "I hope that my Lord will guide me ever closer (even) than this to the right road."