Charles Ellicott Commentary Leviticus 21:10

"And he that is the high priest among his brethren, upon whose head the anointing oil is poured, and that is consecrated to put on the garments, shall not let the hair of his head go loose, nor rend his clothes;" — Leviticus 21:10 (ASV)

And he who is the high priest among his brethren. —That is, among his priestly brethren, the one who is distinguished among them by this office.

On whose head the anointing oil was poured. —This profuse pouring of oil was the distinctive feature in the consecration of the high priest. (See Leviticus 8:12.)

Consecrated to put on the garments. —Better, consecrated by putting on the garments. The robing of the high priest by Moses, as well as anointing him, constituted part of the consecration ceremony. (See Leviticus 8:7-11.)

Shall not uncover his head. —Better, shall not let his head be dishevelled, which was a sign of mourning. (See Leviticus 10:6.)

Nor rend his clothes. —That is, “in the time of distress,” as the ancient Chaldee version of Jonathan rightly adds after it. Sustaining this high position, and being the intercessor between God and man, such outward expressions of sorrow might lead those on whose behalf he ministers in the sanctuary to believe that he thereby impugns the justice of the Divine judgment.