سورة Al-Kahf ( The Cave ) - الآية 22

(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.