2 Kings 6:12

And one of his servants said, none, my lord, O king
He believed everyone of his counsellors were true and faithful to him:

but Elisha the prophet, that is in Israel, telleth the king of Israel
the words that thou speakest in thy bedchamber;
what is said in the most private place, and in the most secret manner: this man had heard much of Elisha, by Naaman, very probably; or perhaps he had attended him in his journey to Israel for a cure, and so might have personal knowledge of Elisha, and be acquainted with the affair of Gehazi; from whence he concluded, that he, who had the thoughts of men revealed to him, had knowledge of their words and counsels, though ever so secret; see ( Ecclesiastes 10:20 ) .