Leviticus 8:23-24

23Moses slaughtered the ram and took some of its blood and put it on the lobe of Aaron’s right ear, on the thumb of his right hand and on the big toe of his right foot.

24Moses also brought Aaron’s sons forward and put some of the blood on the lobes of their right ears, on the thumbs of their right hands and on the big toes of their right feet. Then he splashed blood against the sides of the altar.