Leviticus 22:25-29

Neither from a stranger’s hand shall ye offer the bread of your God of any of these; because their corruption is in them, and blemishes be in them: they shall not be accepted for you.

And the LORD spake unto Moses, saying,

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 unto the LORD.

And whether it be cow or ewe, ye shall not kill it and her young both in one day.

And when ye will offer a sacrifice of thanksgiving unto the LORD, offer it at your own will.