2. When he shall be sent—before the appearing of the Messiah, which, because it was the judgment of this world, and introduced the ruin of the Jewish church and nation, is here called the coming of the great and dreadful day of the Lord. John Baptist gave them fair warning of this when he told them of the wrath to come (that wrath to the uttermost which was hastening upon them) and put them into a way of escape from it, and when he told them of the fan in Christ's hand, with which Christ would thoroughly purge his floor; see Matt. iii. 7, 10, 12. That day of Christ, when he came first, was as that day will be when he comes again—though a great and joyful day to those that embrace him, yet a great and dreadful day to those that oppose him. John Baptist was sent before the coming of this day, to give people notice of it, that they might get ready for it, and go forth to meet it.