(2.) To speak powerfully, and as one that had authority from God, v. 10. It is a strange commission that is here given him: See, I have this day set thee over the nations and over the kingdoms. This sounds very great, and yet Jeremiah is a poor despicable priest still; he is not set over the kingdoms as a prince to rule them by the sword, but as a prophet by the power of the word of God. Those that would hence prove the pope's supremacy over kings, and his authority to depose them and dispose of their kingdoms at his pleasure, must prove that he has the same extraordinary spirit of prophecy that Jeremiah had, else how can be have the power that Jeremiah had by virtue of that spirit? And yet the power that Jeremiah had (who, notwithstanding his power, lived in meanness and contempt, and under oppression) would not content these proud men. Jeremiah was set over the nations, the Jewish nation in the first place, and other nations, some great ones besides, against whom he prophesied; he was set over them, not to demand tribute from them nor to enrich himself with their spoils, but to root out, and pull down, and destroy, and yet withal to build and plant. [1.] He must attempt to reform the nations, to root out, and pull down, and destroy idolatry and other wickednesses among them, to extirpate those vicious habits and customs which had long taken root, to throw down the kingdom of sin, that religion and virtue might be planted and built among them. And, to the introducing and establishing of that which is good, it is necessary that that which is evil be removed. [2.] He must tell them that it would be well or ill with them according as they were, or were not, reformed. He must set before them life and death, good and evil, according to God's declaration of the method he takes with kingdoms and nations, ch. xviii. 9-10. He must assure those who persisted in their wickedness that they should be rooted out and destroyed, and those who repented that they should be built and planted. He was authorized to read the doom of nations, and God would ratify it and fulfil it (Isa. xliv. 26), would do it according to his word, and therefore is said to do it by his word. It is thus expressed partly to show how sure the word of prophecy is—it will as certainly be accomplished as if it were done already, and partly to put an honour upon the prophetic office and make it look truly great, that others may not despise the prophets nor they disparage themselves. And yet more honourable does the gospel ministry look, in that declarative power Christ gave his apostles to remit and retain sin (John xx. 23), to bind and loose, Matt. xviii. 18.