Lévitique 10:15

The shoulder of the separation and the elevated breast with the fats of the oblations they shall bring to be uplifted an elevation before the Lord, and they shall then be thine and thy sons' with thee, by an everlasting statute, as the Lord commanded.

THE THIGH OF HEAVING AND THE BREAST OF WAVING. “This expression is similar to the verse, [the breast of the wave-offering, and the thigh of the heave-offering], which is waved, and which is heaved up. ‘Waving’ is an expression for moving to and fro [in a horizontal direction]. ‘Heaving’ is an expression for moving up and down. But why Scripture divided them, mentioning ‘heaving’ in connection with the thigh and ‘waving’ in connection with the breast, I do not know, for both of them [required] waving and heaving.” Thus far is the language of Rashi.
It appears to me that the reason for it is that during the [seven days of] consecration, the thigh was a heave-offering to G-d, being burned together with the bread and the fats, and that which is set aside from a peace-offering [to be burnt on the altar] is called “a heave-offering,” just as it is said, And of it he shall offer one out of each offering for a heave-offering unto the Eternal, and [it follows] all the more so that these parts [of the ram of consecration] offered on the altar, were all “a heave-offering unto the Eternal.” [Hence the expression “the thigh of heaving.”] It was not called by the term “waving,” for that movement [to and fro in a horizontal direction] was done to the thigh together with the fats and the bread so as to burn them unto the Eternal. The breast, however, was waved by itself, and was only different from the rest of the meat [which was to be eaten by the priests] in that it was waved, and it was through this waving alone that it became sanctified and that Moses acquired it as his portion. [Moses] shalt take the breast of Aaron’s ram of consecration, and wave it for a wave-offering before the Eternal; and it shall be thy portion. Now since the right of Aaron and his sons to the breast and thigh [of peace-offerings] in future generations was [derived] from the day of their consecration as priests, when they acquired the thigh through its being a heave-offering to G-d and the breast through its being waved, whilst the rest of the meat belonged to the owners, therefore the thigh was forever called [the thigh of] “heaving,” and the breast that of “waving,” as was done to them on the day of [the priests] acquiring their rights to them.

יביאו להניף...והיה לך ולבניך, you will not be able to claim these until after the waving has been performed. In other words, this is not a “kick back” from G’d’s “Table.”