Thou shalt take the breast. Henceforth Aaron and his sons were to have the breast of all wave-offerings (Le 7:31-34); but on this occasion, as Moses officiated, the breast was to be his.
A short digression is here made, from this particular offering, to all future offerings for consecration. For the future both the breast and the right shoulder are to belong to the priests. The shoulder, moreover, is to be "heaved," and only the breast "waved; …. heaving" being a single lifting up of the offering towards heaven, while" waving" was a repeated movement in a horizontal direction. Wave and heave offerings are always connected with the portions of the priests, or with things dedicated to God's service. (See Exodus 25:2; Exodus 35:22, Exodus 35:24; Exodus 38:24, Exodus 38:29; Le 7:30-34; Numbers 18:11, Numbers 18:19, Numbers 18:24, etc.)
Here we have a second digression, also concerning future consecrations. The holy garments made for Aaron were to be preserved after his death, and used at the consecration of each successive high priest, who was to be anointed and consecrated in them, and to wear them for seven days from the time that he entered upon his office. Eleazar's investment in them is mentioned (Numbers 20:28); but not that of any later high priest.