Exodus 10:24-26

Then Pharaoh called to Moses and said, “Go, serve the LORD; only let your flocks and your herds be kept back. Let your little ones also go with you.” But Moses said, “You must also give us sacrifices and burnt offerings, that we may sacrifice to the LORD our God. Our livestock also shall go with us; not a hoof shall be left behind. For we must take some of them to serve the LORD our God, and even we do not know with what we must serve the LORD until we arrive there.”