Thou shalt break them with a rod of iron. It is said that these words, and those of the next clause, "cannot describe the mild rule of Christ" (Rosenmuller, Do Wette, Hupfeld, etc.). But the objectors forget that there is a severe, as well as a mild, side to the dealings of God with his human creatures.
St. Paul notes in the same verse both the "severity" and the "goodness" of God (Romans 11:22). Christ, though "the Prince of Peace," "came to send a sword upon the earth" (Matthew 10:34). As' the appointed Judge of men, he takes vengeance on tile wicked, while he rewards the righteous (Luke 3:17; Matthew 25:46).
Nay, St. John, in the Apocalypse, declares that "out of his mouth goeth a sharp sword, that with it he should smite the nations. and "ye shall rule them with a rod of iron" (Revelation 19:15; comp. Revelation 2:27; Revelation 12:5).
So, with respect to the other clause of the verse—Thou shalt dash them in pieces like a potter's vessel—it is to be noted that there is a similar threat made by the Lord of hosts against Jerusalem in the Book of Jeremiah (Jeremiah 19:11), and that under the new covenant the same is threatened in the Revelation (Revelation 2:27).
In truth, both covenants are alike in denouncing the extreme of God's wrath on impenitent sinners, such as those here spoken of.