The Mishna (35b) describes how the kohen gadol performed viduy – confession – on the first sacrifice on his own behalf, asking for forgiveness for his own sins and those of his family. The Mishna teaches that the animal stands with its head facing southward and its face to the west, toward the Holy of Holies.
The Gemara on our daf explains that, in order to do this, the animal is forced to turn its head while the kohen gadol does semikhah (places his hands) on the animal.
The concept of semikhah, where the owner of a korban places both hands on the head of the sacrifice between its horns and presses down on it with all of his strength, applies to all sacrifices with the exception of a bekhor (a first born animal) and ma’aser beheimah (the tenth animal from the flock). It is during semikhah that the owner confesses his sins when the sacrifice comes as part of the process of repentance (a hatat or an asham), or expresses his thanks and praise when the sacrifice is a celebratory one, like a korban shelamim or todah (thanksgiving offering). Immediately after semikhah the korban is slaughtered and sacrificed.
These activities are explained by the Ramban as representing the attitude that the individual should have with regard to his own self. Given that a sin is made up of thought, speech and activity, the person who brings a korban hatat will perform a number of actions, each of which will be an expression of a request for atonement on a separate part of the sin. He will:
- do semikhah on it – representing the activity,
- say viduy on it – representing the speech,
- have the innards of the animal burned on the altar – representing the thoughts and desires of the individual.
Finally, the blood of the sacrifice will be sprinkled on the mizbe’ah, representing his soul. The idea is for the sinner to recognize that he has transgressed against God with his body and soul, and that in order to receive atonement for his actions, what is being done to the sacrifice really should be done to him.