Or HaChaim on Leviticus 16:34/אור החיים על ויקרא ט״ז:ל״ד

1 והיתה זאת לכם לחוקת עולם, "and this shall be for you an eternal statute, etc." This verse refers back to the priests and in particular the High Priest to whom the Torah addressed itself at the beginning of our chapter. The legislation mentioned there is described now as everlasting, i.e. when the facilities exist the procedures of the Day of Atonement are irrevocable. The procedure by means of which atonement is attained on that day contains mystical elements which can only be activated by the High Priest, etc.

2Another reason for the verse here is that we might have thought that the restriction on wearing his golden garments applied only at that time and only to Aaron seeing he himself had been involved in the golden calf episode and it had not yet been fully atoned for. In the future, however, the respective High Priest would be able to discharge his duties in his full regalia. The Torah therefore had to inform us that this is not so. The Torah adds the words לכפר על בני ישראל to tell us that although all of Aaron's share in that sin had been completely erased even in the celestial spheres, the same could not be said of the people. They would need further instalments of atonement year after year indefinitely. Seeing this was so Aaron became part of that vicious circle once again.

3ויעש באשר צוה ה׳ את משה. He did as the Lord commanded Moses. Torat Kohanim writes that this verse is a compliment to Aaron who did not perform all these procedures in order to attain greater stature amongst the people and to aggrandize himself, but who performed all his duties only as a servant of G'd with no ulterior motive. It appears that the Torah also compliments Moses himself seeing that G'd had not spoken to Aaron except via Moses. The Torah goes on record that G'd did not address the person to whom His message was intended directly, but did so only via his trusted servant Moses. When the Torah stated that Aaron complied exactly with what G'd had said, this is proof that Moses had relayed G'd's instructions without adding or omitting one iota. The fact that Moses replicated exactly what G'd told him without adding or detracting is the foundation of our belief in the authenticity of the written Torah, i.e. that it reflects G'd's word no less and no more.