Leviticus 16:4

“He shall put on the holy linen coat, etc.] Which he wore in common with other priests: and he shall have the linen breeches upon his flesh; upon those parts of his body which are more secret, and less honourable flesh, meaning the same, as in (<031502>Leviticus 15:2): and shall be girded with a linen girdle and with the linen mitre shall he be attired, as the other priests were; which were an emblem of the purity and holiness of Christ, whereby he became a proper and suitable high priest, to make atonement for sin, he having none in himself; and of his mean estate of humiliation afflictions, and sufferings, whereby he expiated sin, and made reconciliation for iniquity; the high priest on the…”

“The high priest when he changed his dress on this day was required to bathe himself. In his “golden garments” he had, on this day, and for the previous week, to offer the regular daily sacrifices, and to perform the other sacerdotal duties of the sanctuary, which were usually performed by a common priest. The dress of white linen, which he now put on, appears to have been like the ordinary dress of the common priests, except in the substitution of a linen mitre for the bonnet (or cap), and of a plain linen girdle for the variegated one (Exodus 28:40-43 notes). In preparing to enter the holy of holies, he attired himself in spotless white as a token of the holiness without which none, in a…”

“The linen coat - It is observable, the high - priest did not now use his peculiar and glorious robes, but only his linen garments, which were common to him with the ordinary priests. The reason whereof was, because this was not a day of feasting and rejoicing, but of mourning and humiliation, at which times people were to lay aside their ornaments. These are holy - Because appropriated to an holy and religious use. Leviticus 16:8”

“16:4 For most of the ritual of the Day of Atonement, the high priest wore plain linen clothing rather than his normal robes. This seems to symbolize the humility that should characterize all the people on this solemn occasion. When the high priest stood before God on behalf of his people, he had nothing to commend himself or the people. But when he stood before the people on God’s behalf, his official robes reflected the glory and splendor of God (16:23).”

“holy linen coat: Heb. of holiness, Greek, a sanctified linen coat, This and the other vestures were peculiar for this day, and for the services of this day; that is, for making atonement: the other service, which was ordinary, he performed this day in his other priestly garments. The eight ornaments usually worn by the high priest are enumerated in Exo 28:4, etc., and the four that were for this day are here expressed, and are called the white garments, while the others were designated the golden garments, because some were made with gold thread woven in them. These four were made of six double twisted threads, and of flax only. Lev 6:10; Exo 28:2, Exo 28:39-43, Exo 39:27-29; Isa 53:2; Eze…”