but the breasts and the right thigh Aaron waved for a wave offering before the LORD, as Moses commanded.
These being the first offerings that ever were offered by the levitical priesthood, according to the newly-enacted law of sacrifices, the manner of offering them is particularly related, that it might appear how exactly they agreed with the institution. 1.
Commenting on Leviticus 9:8-22
And Aaron lifted up his hand towards the people, and blessed them,.... After he had offered the above sacrifices both for himself and them: the manner of the priests lifting up their hands when they blessed is thus described; in the provinces the priests lift up their hands to their shoulders, and in the sanctuary above their heads, excepting the high priest, who did not...
And the breasts and the right shoulder Aaron waved [for] a wave offering before the LORD; as Moses commanded. (g) Of the bullock and the ram.