when a prophet speaks in the name of the LORD, if the word does not come to pass or come true, that is a word that the LORD has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him.
22. The prophet hath spoken it presumptuously. He not only condemns the folly and vanity of those who advance their own inventions in the place of God’s commands, but also their arrogance; since doubtless, this is impious and intolerable audacity, to set forth the offspring of man’s earthly brain as if it were a divine revelation.
Here is, I. The promise of the great prophet, with a command to receive him, and hearken to him. Now, 1. Some think it is the promise of a succession of prophets, that should for many ages be kept up in Israel.
Commenting on Deuteronomy 18:15-22
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. (k) Under this sure note he comprises all the other tokens.