New Defender's Study Bible Notes
6:7 the bay. “Bay” should actually read “strong,” and may refer to the “red horses” which are mentioned in Zechariah 6:2, but not Zechariah 6:6-7. The color red may have been deleted to indicate that God will make all war and bloodshed to cease when He restores Israel (Micah 4:1-3).
6:7 walked to and fro. Three times it is stressed that the “strong” horses will “walk to and fro through the earth,” indicating that God will assuredly see that His will is accomplished everywhere, even in the areas still under Babylon’s influence.