Exodus 29:10

And thou shalt cause a bullock to be brought before the tabernacle of the congregation ,.... The same, or of the same kind he was ordered to take, Exodus 29:1 , and here the place is expressed where it was to be taken, and what was to be done with it:

and Aaron and his sons shall put their hands upon the head of the bullock ; not Aaron first alone, and then his sons, as some have thought, Aben Ezra makes mention of; but, as he says, both together, not one before another; declaring it to be their sacrifice, a vicarious one, one in their room and stead, signifying that they deserved to die as that creature would; and by this act putting, as it were, their sins and transgressions upon it, see Leviticus 16:21 and which was an emblem of the imputation of sin to Christ, and laying upon him the iniquities of us all.