The First Born of Clean Beasts: Not Taken from the Dam for Seven Days
Source: TTT
Exodus 22:30
You shall do likewise with your cattle and your sheep. Let them stay with their mothers for seven days, but on the eighth day you are to give them to Me.
Leviticus 22:27
“When an ox, a sheep, or a goat is born, it must remain with its mother for seven days. From the eighth day on, it will be acceptable as an offering made by fire to the LORD.