Exodus 10:24-26

And Pharaoh called to Moses, and said, Go, serve the Lord; let your little ones also go with you; it is only your flocks and your herds that must not go. But Moses said, You must give into our hand also sacrifices and burnt offerings, that we may sacrifice to the Lord our God. Our livestock also shall go with us; there shall not a hoof be left behind; for of them must we take to serve the Lord our God, and we know not with what we must serve the Lord until we arrive there.