What does Exodus 29:20 mean?

Kill the ram, take some of its blood, and put it on Aaron’s right ear, right thumb, and right big toe. Do the same for his sons. Splash the rest of the blood on the sides of the altar. Exodus 29:20 - Modern Text Bible

(Blood is put on the ear, thumb, and toe to show that Aaron and his sons are set apart in everything they hear, do, and wherever they go.)