Charles Ellicott Commentary Zechariah 3:5

"And I said, Let them set a clean mitre upon his head. So they set a clean mitre upon his head, and clothed him with garments; and the angel of Jehovah was standing by." — Zechariah 3:5 (ASV)

Fair — that is, clean. (Compare the words of the Rubric, “a fair white linen cloth.”) The prophet seems to have felt constrained to make the request contained in this verse from an idea that the changing of Joshua’s garments might be only a sign of the removal of the high priest’s own guilt.

Mitre, or turban, on which was fastened the golden plate inscribed with “Holiness to the Lord” , by virtue of which the shortcomings of the sanctuary were atoned (Exodus 28:38). That the prophet was justified in making the request is shown by the fact that it was granted, and that even before the “garments” were put on.

Stood by. — Better, kept standing (where he was).