Jamieson, Fausset and Brown on Zechariah 9:13

13. bent Judah--made Judah as it were My bow, and "filled" it "with Ephraim," as My arrow, wherewith to overcome the successor of the Grecian Alexander, Antiochus Epiphanes (compare Notes, see on Da 8:9; Da 11:32; 1 Maccabees 1:62; 2:41-43), the oppressor of Judah. Having spoken (Zec 9:1-8) of Alexander's victories, after the parenthesis (Zec 9:9, 10) as to Messiah the infinitely greater King coming, he passes to the victories which God would enable Judah to gain over Alexander's successor, after his temporary oppression of them.

O Zion ... O Greece--God on one hand addresses Zion, on the other Greece, showing that He rules all people.