Deuteronomy 15:17

you shall take an awl and pierce a hole through his ear to the door. ¹  Then he will become your servant permanently (this applies to your female servant as well).

Le 25:39-42; 1Sa 1:22

¹ sn When the bondslave’s ear was drilled through to the door, the door in question was that of the master’s house. In effect, the bondslave is declaring his undying and lifelong loyalty to his creditor. The scar (or even hole) in the earlobe would testify to the community that the slave had surrendered independence and personal rights. This may be what Paul had in mind when he said “I bear on my body the marks of Jesus” (Gal 6:17).