The Lord shall be seen over them - Shadowing and refreshing them, as the cloud did the camp in the wilderness.
His arrow shall go forth as the lightning - They shall be conquered in a way that will show that God fights for his followers.
The description here is very sublime; we have a good imitation of it in Nonnus: -
Και τοτε γαιαν ἁπασαν επεκλυσεν ὑετιος Ζευς,π
Πυκνωσας νεφεεσσιν ὁλον πολον· ουρανιη γαρΒρονταιοις παταγοισι Διος μυκησατο σαλπιγξ .
Nonn. Dionys., lib. 6. ver. 229.
"When heaven's dread trumpet, sounding from on high,
Breaks forth in thunders through the darken'd sky;
The pregnant clouds to floods of rain give birth.
And stormy Jove o'erwhelms the solid earth."
J. B. B. C.
In these two verses there is a fine image, and an allusion to a particular fact, which have escaped the notice of every commentator. I must repeat the verses:
Zechariah 9:13; : When I have bent Judah for me, filled the bow with Ephraim, and raised up thy sons, O Zion, against thy sons, O Greece, and made thee as the sword of a mighty man.
Zechariah 9:14; : And the Lord shall be seen over them, and his arrows shall go forth like lightning.
The reader will consult what is said on Hosea 7:16, relative to the oriental bow, which resembles a [figure C] in its quiescent state, and must be recurved in order to be strung. Here, Judah is represented as the recurved bow; Ephraim, as an arrow placed on the string, and then discharged against the Javanites or Greeks with the momentum of lightning; the arrow kindling in its course through the air, and thus becoming the bolt of death to them against whom it was directed.
Volat illud, et incandescit eundo,
Et quos non habuit, sub nubibus invenit ignes.
"It flies apace; and, heating, mounts on high,
Glows in its course, and burns along the sky."
And the Lord shall be seen over them - o“He will reveal himself,” protecting them. Cyril: “He says plainly, that the Lord God will be with them and will fight in serried array with them and will with them subdue those who resist them.” It is as if he would say, “When they go forth and preach everywhere, the Lord shall work with them and confirm the word with signs following” Mark 16:20. “And His arrow shall go forth as the lightning.” Habakkuk directly calls the lightnings the arrows of God: “at the light of Thine arrows they went”. Here it is probably of an invisible agency, and so compared to that awful symbol of His presence, the lightning.
And the Lord God shall blow with the trumpet - As their Commander, ordering their goings. The blowing of the trumpet by the priests in war was commanded, as a reminiscence of themselves before God, “If ye go to war in your land against the enemy that oppresseth you, then ye shall blow an alarm with the trumpets, and ye shall be remembered before the Lord your God, and ye shall be saved from your enemies” Numbers 10:9. Abijah said, “God Himself is with us for our captain, and His priests with sounding trumpets to cry alarm against you” 2 Chronicles 13:12.
And shall go with whirlwinds of the south - As being the most vehement and destructive. So Isaiah, “As whirlwinds in the south sweep by, He cometh from a desert, from a terrible land” Isaiah 21:1. Such smote the four corners of the house where Job‘s children were, and they perished.