For thou hast broken the yoke of his burden, and the staff of his shoulder, the rod of his oppressor, as in the day of Midian.
For thou hast broken the yoke of his burden - The occasion of the "joy," the deliverance not only of Ahaz and Judah from the Assyrian tribute (2 Kings 16:8), and of Israel's Ten tribes from the Assyrian oppressor (2 Kings 15:19), but of the Jewish Christian Church from its last great enemy.
Hast - the past time for the future: in prophetic vision, it expresses the certainty of the event.
The yoke of his burden - the yoke with which he was burdened.
And the staff of his shoulder - the staff which strikes his (Israel's) shoulder (Maurer); or the wood, like a yoke, on the neck of slaves, the badge of servitude (Rosenmuller).
The rod of his oppressor, as in the day of Midian - (Judges 7:8-22.) As Gideon with a handful of men conquered the hosts of Midian, so Messiah, the "child" (Isaiah 9:6; Isaiah 7:14-16), shall prove to be the "Prince of Peace," and the small Israel under Him shall overcome the mighty hosts of Antichrist. Compare Micah 5:2-5, "Bethlehem Ephratah, though thou be little ... yet out of thee shall He come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting ... And he shall stand and feed in the strength of the Lord, in the majesty of the name of the Lord his God ... and this man shall be the Peace, when the Assyrian shall come into our land." This passage of Isaiah contains the same contrast between Messiah's seeming smallness as a child and His omnipotence as the Everlasting One, and alludes also to "the Assyrian," the then enemy of the Church, as here in Isaiah the type of the last great enemy. For further analogies between Gideon's victory and the Gospel, cf. 2 Corinthians 4:7 with Judges 7:22. As the 'dividing of the spoil' (Isaiah 9:3) was followed by that which was 'not joy,' the making of the idolatrous ephod (Judges 8:24-27), so the Gospel victory was soon followed by apostasy at the first, and shall be so again after the millennial overthrow of Antichrist (Revelation 20:3; Revelation 20:7-9), previous to Satan's last doom (Revelation 20:10).