Exodus 22:30
Likewise shalt thou do with thy oxen, and with thy sheep: seven days it shall be with his dam; on the eighth day thou shalt give it to me.
Leviticus 22:27
When a bullock, or a sheep, or a goat is brought forth, then it shall be seven days under the dam; and from the eighth day and thenceforth it shall be accepted for an offering made by fire to the LORD.
Deuteronomy 15:19
All the firstling males that come of thy herd and of thy flock thou shalt sanctify to the LORD thy God: thou shalt do no work with the firstling of thy bullock, nor shear the firstling of thy sheep.
Exodus 13:12
That thou shall set apart to the LORD all that openeth the matrix; and every firstling that cometh of a beast which thou hast, the males shall be the LORD'S.
Leviticus 12:3
And in the eighth day the flesh of his foreskin shall be circumcised.