tn The “wave offering” is תְּנוּפָה (ténufah); it is, of course, cognate with the verb, but an adverbial accusative rather than the direct object. In Lev 23 this seems to be a sacrificial gesture of things that are for the priests—but they present them first to Yahweh and then receive them back from him. So the waving is not side to side, but forward to Yahweh and then back to the priest. Here it is just an induction into that routine, since this is the ordination of the priests and the gifts are not yet theirs. So this will all be burned on the altar.