The entire order of offering sacrifices is described in the Torah in detail, but really this process takes place inside a person, in one’s interior world. Preparation of sacrificial animals, offerings, and the priests’ (Cohen’s) work depends on a person and on one’s spiritual level and intentions associated with this level.
Question: What exactly happens when a person offers a sacrifice to the Creator?
Answer: One takes an egoistic desire and “cuts and eradicates” it, as it is said: “The one who wishes to live has to kill himself.” Then, one revives one’s desire to live for the sake of bestowal. This is what we call “a sacrifice.”
“Sacrifice” (קֻרְבַּן) means “convergence” (קרבה) with the Creator. A person approaches Him to the degree that he even eats food for the sake of bestowal. By offering a sacrifice, one rises from the level of Israel (a direct intention towards the Creator) to the level of Levite and Cohen. At these levels, one offers a sacrifice and receives it back, but now it has an altruistic intention, meaning that one corrects one’s receiving desires and turns them into bestowing. One “eats meat” and “drinks wine,” and by doing so one self-sacrifices for the sake of the Creator, thus getting closer to Him.
These actions are described as slaughtering animals and cooking their meat. While Cohens do this work, Levites “sing.” This is their concrete work that they perform at the three steps named “Israel,” “Cohens,” and “Levites.” While ascending, a person corrects his egoism, the “animal” in him by killing it and preparing it to receive for the sake of giving. This picture differs dramatically from its material description… as it does in all the commandments.