Zechariah 3:4 (ESV) … “And the angel said to those who were standing before him, “Remove the filthy garments from him.” And to him he said, “Behold, I have taken your iniquity away from you, and I will clothe you with pure vestments.”
Joshua the priest is dressed in filthy clothes, but the angel commands those standing nearby to remove the soiled clothes and promises that Joshua will instead be clothed in rich garments. The significance of the filth of Joshua’s clothes is uncertain. Perhaps his clothes are dirty because he is mourning as a sign of repentance; however, the word used to describe these stains on Joshua’s clothes is related to a word used elsewhere for “excrement” (Deut 23:13; Ezek 4:12). With his garments thus fouled, the priest is disqualified from service.
Verse 2 mentions that Joshua is snatched from the fire, indicating that the priest has been rescued from the state described here. The angel instructs those standing near Joshua, probably members of the priestly company (v. 8), to remove the priest’s filthy clothes. Then the angel addresses Joshua directly, declaring that his sins have been taken away and that he will receive rich garments. The noun translated “rich garments” (cf. the TNIV’s “fine garments”) appears elsewhere only in Isaiah 3:22 for special garments worn at festive occasions. Here the instructions concerning Joshua’s clothes represent the removing of the sin that previously stained him and the people of Yahweh whom he represents (Zech 3:9; cf. Isa 64:6). Similar in character to the investiture of priests (Lev 8:1–9), the wording intimates that the reinstatement of Joshua as high priest following the shame of exile requires an act of divine installation.
This vision is highly symbolic and highly significant. The filthy garments indicate that we have no righteousness of our own. The great accuser delights to slander us and parade our faults and failures before God. But “we have an advocate with the Father, Jesus Christ the righteous” (1 John 2:1). He makes His righteousness our righteousness. Whenever Satan tries to raise the issue of our sin, our Advocate simply raises His nail-scarred hands to silence him. God wills out of existence the sins of those who are washed in the blood of the Lamb.
What is true of the Christian believer today was made symbolically true of Joshua in Zechariah’s day and will be made spiritually true of Israel in a coming day. The vision anticipated the glorious day when the nation of Israel will undergo a spiritual rebirth and will be given a spiritual ministry to the nations, as indicated by Joshua’s “fair mitre” (Zechariah 3:5), which was symbolic of his new and effective ministry. The very name “Joshua” (Yeshua) was significant, for it was the Old Testament form of the name Jesus. He is the One who will remove Israel’s national sins, just as He removes our individual sins.
 Ham, C., & Hahlen, M. (2001–). Minor Prophets (pp. 374–375). Joplin, MO: College Press Pub. Co.  Phillips, J. (2009). Exploring the Minor Prophets: An Expository Commentary (Zec 3:1–7). Kregel Publications; WORDsearch Corp.