Deuteronomy 15:17-23

15:17 you shall take an awl and pierce a hole through his ear to the door. Then he will become your servant permanently (this applies to your female servant as well). 15:18 You should not consider it difficult to let him go free, for he will have served you for six years, twice the time of a hired worker; the Lord your God will bless you in everything you do.

Giving God the Best

15:19 You must set apart for the Lord your God every firstborn male born to your herds and flocks. You must not work the firstborn of your bulls or shear the firstborn of your flocks. 15:20 You and your household must eat them annually before the Lord your God in the place he chooses. 15:21 If they have any kind of blemish – lameness, blindness, or anything else – you may not offer them as a sacrifice to the Lord your God. 15:22 You may eat it in your villages, whether you are ritually impure or clean, just as you would eat a gazelle or an ibex. 15:23 However, you must not eat its blood; you must pour it out on the ground like water.