Charles Ellicott Commentary 2 Kings 18:20

"Thou sayest (but they are but vain words), [There is] counsel and strength for the war. Now on whom dost thou trust, that thou hast rebelled against me?" — 2 Kings 18:20 (ASV)

You say (but they are merely vain words). —Literally, you have said — a mere lip-word it was — that is, insincere language, an utterance which you knew to be false. (Compare our expression, “lip-service.”)

I have counsel ... —The margin is wrong.