Exodus 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, ¹  and then splash the blood all around on the altar.

Le 8:24; Le 14:7,16; Le 14:14; Le 16:14,15,19; Isa 50:5; Isa 52:15; Mr 7:33; Heb 9:19-23; Heb 10:22; Heb 12:24; 1Pe 1:2

¹ sn By this ritual the priests were set apart completely to the service of God. The ear represented the organ of hearing (as in “ears you have dug” in Ps 40 or “awakens my ear” in Isa 50), and this had to be set apart to God so that they could hear the Word of God. The thumb and the hand represented the instrument to be used for all ministry, and so everything that they “put their hand to” had to be dedicated to God and appropriate for his service. The toe set the foot apart to God, meaning that the walk of the priest had to be consecrated – where he went, how he conducted himself, what life he lived, all belonged to God now.