R. Eliezer Yuden Berebbi was wont to expound: The boring is done only in the ear-lap. R. Meir says: in the helix. For a Cohein is not bored in that this would render him "blemished," and if boring were in the ear-lap, how would he be rendered blemished thereby? We are hereby taught that boring is only in the height of the ear.
"his ear": It is written here "his ear," and, elsewhere (in respect to a leper) (Vayikra 14:14) "his ear." Just as there, the right ear (is specified), so, here, the right ear (is intended).