Leviticus 8:23-24

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

24Next he brought Aaron’s sons forward, and Moses put some of the blood on their right earlobes, on their right thumbs, and on the big toes of their right feet, and Moses splashed the rest of the blood against the altar’s sides.