Zechariah 6:3

6:3 to the third white horses, and to the fourth spotted horses, all of them strong. ¹ 

Zechariah 13:9

13:9 Then I will bring the remaining third into the fire;

I will refine them like silver is refined

and will test them like gold is tested.

They will call on my name and I will answer;

I will say, ‘These are my people,’

and they will say, ‘The Lord is my God.’” ² 

[6:3]  ¹ tc For the MT reading אֲמֻצִּים (’amutsim, “strong”) Aquila and Syriac presuppose אֲדֻמִּים (’adummim, “red”), thus giving the red horse an assignment and eliminating the problem of a fifth, “spotted” horse. The fourth would be a mottled red horse according to this view. There is, however, no manuscript support for this interpretation.

[13:9]  ² sn The expression I will say ‘It is my people,’ and they will say ‘the Lord is my God’ is reminiscent of the restoration of Israel predicted by Hosea, who said that those who had been rejected as God’s people would be reclaimed and once more become his sons and daughters (Hos 2:23).