Or HaChaim on Leviticus 9:2/אור החיים על ויקרא ט׳:ב׳

1 קח לך עגל, "take for yourself a bull-calf, etc." Yuma 4 questions the need for the words "for yourself," seeing that the Torah goes on to say that the he-goat in verse 3 was for the people; obviously then the bull-calf was for Aaron personally. The Talmud answers that the words קח לך meant that Aaron was to pay for that bull-calf out of his personal funds.

2Perhaps we may add that the word לך was intended as a sign for all times that Aaron had not made the golden calf with sinful intent nor had he been involved in its worship. This is why a bull-calf could serve as atonement for Aaron. The same could not be said of the people at large seeing their involvement in the sin of the golden calf had been במזיד, i.e. they had been aware of what they had been doing. Not only could a bull-calf not serve as atonement for their sin, on the contrary, it would remind G'd of their sin and be an accuser. You will find in Vayikra Rabbah 21,10 that the reason G'd did not want Aaron to enter the Holy of Holies on the Day of Atonement dressed in his golden garments was because he had been the one who made the golden calf and we have a principle of אין קטיגור נעשה סניגר, "something which served once as an accuser cannot reverse its role and serve as advocate for the defence." This was a consideration which did not apply to the Israelites who had sinned knowingly in the way they related to the golden calf so that a bull-calf could not serve as a sin-offering for them.

3In this connection we must explain why G'd commanded Aaron to take a bull-calf as a sin-offering altogther. Is not a sin-offering intended as atonement and there is therefore no more powerful advocate for the defence than such an offering? Apparently G'd judged matters very fairly. On the one hand, Aaron's involvement in the construction of the golden calf was peripheral; he had neither made its shape, nor believed in it when it emerged from the crucible, and, as he explained to Moses: "the calf emerged by itself" (Exodus 32,24), i.e. as a result of an action by the sorcerers Yeynuss and Yombrus amongst the mixed multitude as reported by Tanchuma 19 on Parshat Ki Tissa. It follows therefore that there were steps in the procedure which resulted in the golden calf materialising which Aaron did take knowingly. He told the people to bring the gold; he accepted it from them; he etched the gold with an etching tool. All of these details he performed in full awareness of what he was doing. Even though the reason he did these things was fear of the Israelites killing him just as they had killed his nephew Chur, and even though all he did was stall for time until Moses would return, he did something improper. This is why G'd told him to bring a sin-offering to atone for a sin which he had been instrumental in making possible. Concerning the gold which was the crucial element in that sin, G'd told Aaron not to appear before Him in the Holy of Holies dressed in gold seeing the accuser could not become an advocate for the defence. The same consideration did not apply to the Israelites as they had been involved in that sin knowingly and a bull-calf could not therefore be used as a sin-offering on their behalf. G'd therefore commanded the Israelites to prepare a he-goat as their sin-offering.

4We have to question how it is possible that in view of the principle (Rosh Hashana 26) that the accuser cannot serve as an advocate for the defence that the Talmud Erchin 16 tells us that the purpose of the four golden garments of the High Priest was to atone for four different categories of sin. In view of this the accuser certainly did turn advocate for the defence! We must answer therefore that one cannot compare the process of atonement which occurs as a result of offerings presented on the copper altar outside the Tabernacle with the process of atonement initiated by offerings presented on the golden altar inside the Sanctuary. The function of the golden altar inside the Sanctuary is to cleanse the people from sin absolutely so that not a trace of their former sins remain. The well-known symbol for this was the red cord hung at the cliff from where the scapegoat was thrown off, which turned white as a result of the atonement procedures performed by the High Priest inside the Sanctuary being accepted by G'd (compare Yuma 67). The golden garments worn by the High Priest when he performed duties outside the Sanctuary did not interfere with the atonement process because that atonement process did not result in a complete removal of all vestiges of guilt. In order to achieve such total atonement, the High Priest could not wear anything in the Sanctuary which would remind G'd of his ever having been associated with the sin of the golden calf. The very fact that Aaron was commanded to wear the golden garments when performimg his duties on the copper altar was proof that his involvement with the golden calf had only been peripheral. The Israelites, whose sin had been far greater, could not obtain their forgiveness through any process performed only on the copper altar outside the Sanctuary.