Whoever kills an animal must make restitution, but whoever kills a man must be put to death.
Killing an animal requires restitution, but killing a human being requires death.
This verse restates the difference between restitution and capital penalty.
17And if a man takes the life of anyone else, he must surely be put to death. 18Whoever kills an animal must make restitution — life for life. 19If anyone injures his neighbor, whatever he has done must be done to him: 20fracture for fracture, eye for eye, tooth for tooth. Just as he injured the other person, the same must be inflicted on him. 21Whoever kills an animal must make restitution, but whoever kills a man must be put to death. 22You are to have the same standard of law for the foreign resident and the native; for I am the LORD your God.’” 23Then Moses spoke to the Israelites, and they took the blasphemer outside the camp and stoned him. So the Israelites did as the LORD had commanded Moses.