The land of the north, i.e., the territory covered by the lands of the Euphrates and Tigris, and the land of the south, i.e., Egypt, are mentioned as the two principal seats of the power of the world in its hostility to Israel: Egypt on the one hand, and Asshur-Babel on the other, which were the principal foes of the people of God, not only before the captivity, but also afterwards, in the conflicts between Syria and Egypt for the possession of Palestine (Dan. Dan. 11:1). . . . Then follow the white horses, indicating that the judgment will lead to complete victory over the power of the world. Into the south country, i.e., to Egypt, the other representative of the heathen world-power, goes the chariot with the speckled horses, to carry the manifold judgment of death by sword, famine, and pestilence, which is indicated by this colour.4
The black horses go to Babylon, primarily to represent the awful desolation with which Darius visited it in the fifth year of his reign (two years after this prophecy) for revolting [Henderson]. The white go after the black horses to the same country; two sets being sent to it because of its greater cruelty and guilt in respect to Judea. The white represent Darius triumphant subjugation of it [Moore]. Rather, I think, the white are sent to victoriously subdue Medo-Persia, the second world kingdom, lying in the same quarter as Babylon, namely, north.5
The emphasis given is fitting for in the fifth year of Darius (three years after the prophet saw these visions); Babylon, which had been conquered by Cyrus, revolted against Darius and experienced devastation and depopulation in retaliation. When these things happened, Zechariah and the Israel of his day could know that truly the spirit (i.e., the wrath of God, cf. Zec. Zec. 1:15; Eze. Eze. 5:13; Eze. 24:13) was quieted (i.e., was satisfied) in the north country.6But where do the red horses ride? One view explains the red horses as the strong steeds which, rather than riding in a single direction, are commanded to walk to and fro throughout the earth (Zec. Zec. 6:6-7).
It should be observed that the red horses (cf. Zec. Zec. 6:2) seemingly are assigned no mission and that the bay horses are separated from the grizzled, whereas in Zec. Zec. 6:3 they appear to be together. While it does not solve the problem completely, it seems best to view the black . . . white . . . and the grizzled as being references to the second, third, and fourth chariots that are sent on specific missions and that the bay in Zec. Zec. 6:7 should be taken not to denote a color, but to denote a characteristic, i.e., strong (the Heb. word ʿamōts can denote strength as well as a deep red color). If this understanding is correct, then the bay in Zec. Zec. 6:7 is a reference to the red horses drawing the first chariot of verse Zec. Zec. 6:2. While the second, third, and fourth chariots are off on their specific missions, the first chariot engages in a general mission of going to and fro through the earth (mentioned three times in Zec. Zec. 6:7, an indication that their task is every bit as important as that undertaken by the other chariots). Their mission throughout all the earth is indicative that war and bloodshed will hold sway throughout all the world. The reference to the earth must be understood in a much broader sense than just to the land of Israel. It must be understood as being a reference to the earth universally.7This view notes that whereas the black, white, and dappled horses are all given specific destinations, Zechariah Zec. 6:6 indicates a global scope for the strong steeds. Others understand the strong steeds and their walking to and fro throughout the earth as referring to the collective whole. Another explanation is that the red horses seen by Zechariah had already drawn their chariot in empowering Medo-Persias overthrown of Babylon:
Now, when these visions were shown to Zechariah, Babylon had already been overthrown, and its world-empire taken away, visibly and apparently, by the Medo-Persians, behind whom, however (as the prophet beholds), there was the invisible chariot of God, with its red horses of blood and vengeance. This act of judgment on the first great Gentile world-power which had oppressed Israel and laid waste his land being already an accomplished fact (though in the 3rd verse, for completeness sake, all the four are shown to the prophet together . . . ), this first chariot is passed over by the Angel in the interpretation, and is not seen among those who go forth in Zec. Zec. 6:6its mission, as far as the Babylonian Empire is concerned, having already been fulfilled.8