John Gill's Bible Commentary Ver. 1. If there arise among you a prophet , etc.] A false prophet, a lying prophet, as the Targum of Jonathan; one that pretends to be a true prophet, and to be sent of God, and to come from him with a message from him, a new revelation or doctrine, or in his name, to foretell things to come; the former is chiefly meant. Such prophets did arise in Israel before the time of Christ, and have since arose under the Christian name; (see 2 Peter 2:1), or a dreamer of dreams ; the same with the prophet, only to be distinguished by the different manner of their having the mind and will of God revealed to them, pretended to; either by vision or by dream, which were the two usual ways in which the Lord spake to the true prophets, ( Numbers 12:6) so that the prophet is one who pretended he had a vision from the Lord, and the dreamer one that had a dream from him, or something revealed to him in a dream; and dreams are sometimes used for false doctrines, vain, deceitful, and illusory; (see Jeremiah 23:25-28).
The Targum of Jonathan calls him “a dreamer of a dream of pride:” such persons are generally prompted by the pride of their own hearts to take such a method to make themselves famous and respected among men; and usually bring such doctrines with them which are agreeable to the pride and vanity of human nature: and giving thee a sign or a wonder ; for the confirmation of his mission and doctrine; such as Moses wrought before the children of Israel and before Pharaoh. Signs are expressions or representations of things to come to pass; wonders, such as either do, or seem to exceed the common course of nature, or be contrary to it.
Matthew Henry Commentary
Verses 1-5 - Moses had cautioned against the peril that might arise from the Canaanites. Here he cautions against the rise of idolatry amon themselves. It is needful for us to be well acquainted with the truth and precepts of the Bible; for we may expect to be proved by temptations of evil under the appearance of good, of error in the guis of truth; nor can any thing rightly oppose such temptations, but the plain, express testimony of God's word to the contrary. And it would be a proof of sincere affection for God, that, notwithstanding speciou pretences, they should not be wrought upon the forsake God, and follo other gods to serve them.
Original Hebrew כי3588 יקום6965 בקרבך7130 נביא5030 או176 חלם2492 חלום2472 ונתן5414 אליך413 אות226 או176 מופת׃4159