Zech 3:8

3:8 they are men who are a sign. These men foreshadow the coming Servant because they are priests, and He will act as a priest by making atonement for sin (v. 9 note).

my servant. A title of honor initially used for Moses (Num. 12:6–8). The term also was used as a title in Isaiah, sometimes for Israel (Is. 41:8; 44:1, 2) and sometimes (as here) for the Messiah, the Servant who would redeem His people (Is. 42:1–7; 52:13).

the Branch. A Messianic title combining the offices of priest and king (6:12 note: Is. 4:2 and note).