GOD'S WORD® Translation
If a prophet speaks in the LORD's name and what he says doesn't happen or come true, then it didn't come from the LORD. That prophet has spoken on his own authority. Never be afraid of him.

American Standard Version
when a prophet speaketh in the name of Jehovah, if the thing follow not, nor come to pass, that is the thing which Jehovah hath not spoken: the prophet hath spoken it presumptuously, thou shalt not be afraid of him.

Berean Study Bible
When a prophet speaks in the name of the LORD and the message does not come to pass or come true, that is a message the LORD has not spoken. The prophet has spoken presumptuously. Do not be afraid of him.

Douay-Rheims Bible
Thou shalt have this sign: Whatsoever that same prophet foretelleth in the name of the Lord, and it cometh not to pass: that thing the Lord hath not spoken, but the prophet hath forged it by the pride of his mind: and therefore thou shalt not fear him.

English Revised Version
when a prophet speaketh in the name of the LORD, if the thing follow not, nor come to pass, that is the thing which the LORD hath not spoken: the prophet hath spoken it presumptuously, thou shalt not be afraid of him.

King James Bible
When a prophet speaketh in the name of the LORD, if the thing follow not, nor come to pass, that is the thing which the LORD hath not spoken, but the prophet hath spoken it presumptuously: thou shalt not be afraid of him.

World English Bible
when a prophet speaks in the name of Yahweh, if the thing doesn't follow, nor happen, that is the thing which Yahweh has not spoken: the prophet has spoken it presumptuously, you shall not be afraid of him.

Young's Literal Translation
that which the prophet speaketh in the name of Jehovah, and the thing is not, and cometh not -- it is the word which Jehovah hath not spoken; in presumption hath the prophet spoken it; -- thou art not afraid of him.

Deuteronomy 18:22 Additional Translations ...