Leviticus 8:22-23

²²Then he/I brought the other ram, the one for consecrating the priests, and Aaron and his sons laid their hands on its head.

²³Moses/I slaughtered that ram, drained some of its blood in a bowl, and put some of that blood on the lobes of the right ears, the thumbs of the right hands, and the big toes of the right feet of Aaron and his sons to indicate that what they listened to and what they did and where they went should be directed by Yahweh.