I. A prophecy of the appearing of his forerunner John the Baptist, which the prophet Isaiah had foretold (ch. xl. 3), as the preparing of the way of the Lord, to which this seems to have a reference, for the words of the latter prophets confirmed those of the former: Behold, I will send my messenger, or I do send him, or I am sending him. "I am determined to send him; he will now shortly come, and will not come unsent, though to a careless generation he comes unsent for." Observe, 1. He is God's messenger; that is his office; he is Malachi (so the word is), the same with the name of this prophet; he is my angel, my ambassador. John Baptist had his commission from heaven, and not of men. All held John Baptist for a prophet, for he was God's messenger, as the prophets were, and came on the same errand to the world that they were sent upon—to call men to repentance and reformation. 2. He is Christ's harbinger: He shall prepare the way before me, by calling men to those duties which qualify them to receive the comforts of the Messiah and his coming, and by taking them off from a confidence in their relation to Abraham as their father (which, they thought, would serve their turn without a saviour), and by giving notice that the Messiah was now at hand, and so raising men's expectations of him, and making them readily to go into the measures he would take for the setting up of his kingdom in the world. Note, God observes a method in his work, and, before he comes, takes care to have his way prepared. This is like the giving of a sign. The church was told, long before, that the Messiah would come; and here it is added that, a little before he appears, there shall be a signal given; a great prophet shall arise, that shall give notice of his approach, and call to the everlasting gates and doors to lift up their heads and give him admission. The accomplishment of this is a proof that Jesus is the Christ, is he that should come, and we are to look for no other; for there was such a messenger sent before him, who made ready a people prepared for the Lord, Luke i. 17. The Jewish writers run into gross absurdities to evade the conviction of this evidence; some of them say that this messenger is the angel of death, who shall take the wicked out of this life, to be sent into hell torments; others of them say that it is Messiah the son of Joseph, who shall appear before Messiah the son of David; others, this prophet himself; others, an angel from heaven: such mistakes do those run into that will not receive the truth.