Exodus 22:30
You shall do likewise with your cattle and with your sheep. Seven days it shall be with its mother, then on the eighth day you shall give it to me.
Leviticus 22:27
"When a bull, or a sheep, or a goat, is born, then it shall remain seven days with its mother; and from the eighth day and thenceforth it shall be accepted for the offering of an offering made by fire to the LORD.
Deuteronomy 15:19
All the firstborn males that are born of your herd and of your flock you shall sanctify to the LORD your God: you shall do no work with the firstborn of your herd, nor shear the firstborn of your flock.
Exodus 13:12
that you shall set apart to the LORD all that opens the womb, and every firstborn which you have that comes from an animal. The males shall be the LORD's.
Leviticus 12:3
In the eighth day the flesh of his foreskin shall be circumcised.