Exodus 29:10 And thou shalt cause a bullock to be brought before the tabernacle of the congregation: and Aaron and his sons shall put their hands upon the head of the bullock. - Free Bible Online

      10-22. And thou shalt cause a bullock to be brought before the tabernacle--This part of the ceremonial consisted of three sacrifices: (1) The sacrifice of a bullock, as a sin offering; and in rendering it, the priest was directed to put his hand upon the head of his sacrifice, expressing by that act a consciousness of personal guilt, and a wish that it might be accepted as a vicarious satisfaction. (2) The sacrifice of a ram as a burnt offering (Ex 29:15-18). The ram was to be wholly burnt, in token of the priest's dedication of himself to God and His service. The sin offering was first to be presented, and then the burnt offering; for until guilt be removed, no acceptable service can be performed. (3) There was to be a peace offering, called "the ram of consecration" (Ex 29:19-22). And there was a marked peculiarity in the manner in which this other ram was to be disposed of. The former was for the glory of God--this was for the comfort of the priest himself; and as a sign of a mutual covenant being ratified, the blood of the sacrifice was divided--part sprinkled on the altar round about, and part upon the persons and garments of the priests. Nay, the blood was, by a singular act, directed to be put upon the extremities of the body, thereby signifying that the benefits of the atonement would be applied to the whole nature of man. Moreover, the flesh of this sacrifice was to be divided, as it were, between God and the priest--part of it to be put into his hand to be waved up and down, in token of its being offered to God, and then it was to be burnt upon the altar; the other part was to be eaten by the priests at the door of the tabernacle--that feast being a symbol of communion or fellowship with God. These ceremonies, performed in the order described, showed the qualifications necessary for the priests. (See Heb 7:26, 27; 10:14).

JFB.