Leviticus 23:20 - Joseph Benson’s Commentary on the Old and New Testaments

Wave them Some part of them, in the name of the whole; and so for the two lambs otherwise they had been too large and too heavy to be waved. For the priests Who had to themselves not only the breast and shoulder, as in other sacrifices which belonged to the priest, but also the rest which belonged to the offerer; because the whole congregation being the offerers here, it could neither be distributed to them all, nor given to some without offence to the rest.