Deuteronomy 12:6
6 and there you shall bring your burnt offerings and your sacrifices, kyour tithes and the contribution that you present, your vow offerings, your freewill offerings, and the lfirstborn of your herd and of your flock.
Deuteronomy 15:19
19 d“All the firstborn males that are born of your herd and flock you shall dedicate to the Lord your God. You shall do no work with the firstborn of your herd, nor shear the firstborn of your flock.