John Calvin Commentary 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 the oblation of an offering made by fire unto Jehovah." — Leviticus 22:27 (ASV)

When a bullock or a sheep. God forbids the young to be taken from the womb to the altar. This prohibition exists not only because this bad example was likely to be transferred from the sacrifices to ordinary food, but also because the offering would have been fraudulent.

We have seen that the sacrifices were called the bread of God, so that people would be more generous concerning them and not offer meager victims. To kill a young animal fresh from the womb would have been a sign of contempt. However, consideration was also given to humanity, to prevent them from becoming accustomed to cruelty by eating such sacrifices.

The eighth day is appointed as the time when the offering may lawfully begin. I am afraid that the reason some assign for this is too subtle—namely, that an animal is perfected in seven days because God completed the work of creation in seven days. Furthermore, on this basis, the seventh day would be the most fitting for sacrifice, because God completed all His work in six days, and the seventh was hallowed for His service. It is enough for me that consideration was given to maturity of age, just as in the case of circumcision.²⁹⁶

²⁹⁶ This closing sentence is omitted in Fr.