سورة Al-Kahf ( The Cave ) - الآية 22

Some will say, “They were three, their dog was the fourth,” while others will say, “They were five, their dog was the sixth,” – merely guessing at the unseen. And others will say, “They were seven, their dog was the eighth.” Say, “My Lord knows best their number; no one knows about them except a few[14]. So do not argue about them except in a brief manner, nor ask anyone about them.”