I put on righteousness - Or “justice” - as a magistrate, and in all his transactions with his fellow-men. It is common to compare moral conduct or traits of character with various articles of apparel; compare Isaiah 11:5, note; Isaiah 61:10, note.
And it clothed me - It was my covering; I was adorned with it. So we speak of being “clothed with humility;” and so, also, of the “garments of salvation.”
My judgment - Or rather justice - particularly as a magistrate.
Was as a robe - The word “robe” (מעיל me‛ı̂yl) denotes the “mantle” or outer garment that is worn by an Oriental. It constitutes the most elegant part of his dress; Notes at Isaiah 6:1. The idea is, that his strict justice was to him what the full flowing robe was in apparel. It was that for which he was best known; that by which he was distinguished, as one would be by an elegant and costly robe.
And a diadem - Or, “turban”. The word used here צניף tsânı̂yph - is from צנף tsânaph, to roll, or wind around, and is applied to the turban, because it was thus wound around the head. It is applied to the mitre of the high priest Zechariah 3:5, and may also be to a diadem or crown. It more properly here, however, denotes the “turban,” which in the East is an essential part of dress. The idea is, that he was fully clad or adorned with justice.