This is a symbolic action that identifies the Levites with the animals being offered. In this way the person is offering himself through the animal to Yahweh. (See: [[rc://en/ta/man/translate/translate-symaction]])
Aaron was to present the Levites to Yahweh as if he were lifting up an offering to Yahweh. AT: "dedicate them to me, as if you were lifting them up a wave offering to me" (See: [[rc://en/ta/man/translate/figs-simile]])