Hashem instructs the kohanim to exercise extreme care when they enter the Mishkan. On Yom Kippur, the Kohen Gadol (High Priest) is to approach the holiest part of the Mishkan after special preparations and wearing special clothing. He brings offerings unique to Yom Kippur, including two identical goats that are designated by lottery. One is "for Hashem, and is offered in the Temple, while the other is "for Azazel," to be in the desert. The Torah states the individual's obligations on Yom Kippur: On the 10th day of the seventh month, one must “afflict” oneself. We are to abstain from eating and drinking, anointing, wearing leather footwear, washing and marital relations.

Consumption of blood is prohibited. The blood of slaughtered birds and undomesticated beasts must be covered. The people are warned against engaging in the wicked practices that were common in Egypt. Incest is defined and prohibited. Marital relations are forbidden during a woman's monthly cycle. Homosexuality, bestiality and child sacrifice are prohibited.

The Power of Silence

The Kohen Gadol, the High Priest, would come into the Holy of Holies only once a year, and his first service in that awesome place and on that awesome day was not to seek forgiveness for the people for the sins of spiritual contamination, of rebellion either through desire or even for thoughts of atheism, or for that matter, any sin between man and God. Rather, it was to seek atonement for gossip and slander — the sins that destroy the cohesion of society, that break the bond between one person and another.

The tongue can give life and the tongue can kill as it says in Mishlei, Proverbs (18:21), “Death and life and in the hand of the tongue.” The agency of the atonement on Yom Kippur is through the ketoret — the spice offering. It is the nose that senses the ketoret, and it is the nose that can discern between life and death. Life was breathed into man through his nostrils, and thus the first organ that can detect the absence of life — death — is the nose. When things die, they smell offensive, and nothing is more offensive than a human cadaver, the greatest recipient of life.

It is specifically Aharon who can bring atonement for the sins of the mouth because it was Aharon who was able to be silent in the face of the greatest tragedy, when he lost two sons on the same day, as it says, “And Aharon was silent…” (10:3)