Exodus 29:20

29:20 and you are to kill the ram and take some of its blood and put it on the tip of the right ear of Aaron, on the tip of the right ear of his sons, on the thumb of their right hand, and on the big toe of their right foot, and then splash the blood all around on the altar.

Exodus 21:6

21:6 then his master must bring him to the judges, and he will bring him to the door or the doorposts, and his master will pierce his ear with an awl, and he shall serve him forever.