And I said, Let them set a fair mitre upon his head. So they set a fair mitre upon his head, and clothed him with garments. And the angel of the LORD stood by.
And I said, Let them set a fair mitre upon his head. Here the prophet, rejoicing at the change of raiment so far made, interposes to ask for the crowning assurance that the priesthood would be fully restored-namely, the putting the mitre or priestly turban on Joshua: its fair colour symbolizing the official purity of the order restored. He does not command, but prays: not "set," but "let them set." The Vulgate and Syriac versions read it, 'He then said,' which is the easier reading; but the very difficulty of the present Hebrew reading makes it less likely to come from a modern corrector of the text.
And the angel of the Lord stood by - the Divine Angel had been sitting (the posture of a judge, Daniel 7:9); now He "stands" to see that Zechariah's prayer be executed, and then to give the charge (Zechariah 3:6-7).