“Aaron shall present the bull as a sin offering for himself, and shall make atonement for himself and for his house. He shall kill the bull as a sin offering for himself.
The Jewish writers say that for seven days before the day of expiation the high priest was to retire from his own house, and to dwell in a chamber of the temple, that he might prepare himself for the service of this great day.
Commenting on Leviticus 16:5-14
And Aaron shall bring the bullock of the sin offering which is for himself,.... In the same manner, and is to be understood in the same sense as in Lev 16:6, and shall make atonement for himself and for his house: by a confession of words, as the Targum of Jonathan adds, and which Jarchi calls the second confession; for the same was made, and...
Aaron shall bring the bullock of the sin offering which is for himself, &c.--The first part of the service was designed to solemnize his own mind, as well as the minds of the people, by offering the sacrifices for their sins.