Albert Barnes Commentary Leviticus 8:7-9

"And he put upon him the coat, and girded him with the girdle, and clothed him with the robe, and put the ephod upon him, and he girded him with the skilfully woven band of the ephod, and bound it unto him therewith. And he placed the breastplate upon him: and in the breastplate he put the Urim and the Thummim. And he set the mitre upon his head; and upon the mitre, in front, did he set the golden plate, the holy crown; as Jehovah commanded Moses." — Leviticus 8:7-9 (ASV)

See the notes at Exodus 28:0.

Leviticus 8:9. The holy crown – The golden plate of the mitre was so called as the distinctive badge of the high priest’s consecration. See Leviticus 21:12.