8. by night--The Jews begin their day with sunset; therefore the night which preceded the twenty-fourth day of the month is meant (Zec 1:7).
      a man--Jehovah, the second person of the Trinity, manifested in man's form, an earnest of the incarnation; called the "angel of Jehovah" (Zec 1:11, 12), "Jehovah the angel of the covenant" (Mal 3:1; compare Ge 16:7 with Zec 1:13; Ge 22:11 with Zec 1:12; Ex 3:2 with Zec 1:4). Being at once divine and human, He must be God and man in one person.
      riding--implying swiftness in executing God's will in His providence; hastening to help His people.
      red horse--the color that represents bloodshed: implying vengeance to be inflicted on the foes of Israel (compare 2Ki 3:22; Isa 63:1, 2; Re 6:4); also fiery zeal.
      among the myrtle trees--symbol of the Jewish Church: not a stately cedar, but a lowly, though fragrant, myrtle. It was its depressed state that caused the Jews to despond; this vision is designed to cheer them with better hopes. The uncreated angel of Jehovah's presence standing (as His abiding place, Ps 132:14) among them, is a guarantee for her safety, lowly though she now be.
      in the bottom--in a low place or bottom of a river; alluding to Babylon near the rivers Euphrates and Tigris, the scene of Judah's captivity. The myrtle delights in low places and the banks of waters [PEMBELLUS]. MAURER translates, from a different root, "in a shady place."
      red horses--that is, horsemen mounted on red horses; Zec 1:10, 11, confirm this view.
      speckled . . . white--The "white" implies triumph and victory for Judah; "speckled" (from a root "to intertwine"), a combination of the two colors white and red (bay [MOORE]), implies a state of things mixed, partly prosperous, partly otherwise [HENDERSON]; or, the connection of the wrath (answering to the "red") about to fall on the Jews' foes, and triumph (answering to the "white") to the Jews themselves in God's arrangements for His people [MOORE]. Some angels ("the red horses") exercised offices of vengeance; others ("the white"), those of joy; others ("the speckled"), those of a mixed character (compare Zec 6:2, 3). God has ministers of every kind for promoting the interests of His Church.

JFB.