Numbers 35:9-12

9The Lord said to Moses,

10“Give the following instructions to the people of Israel. “When you cross the Jordan into the land of Canaan,

11designate cities of refuge to which people can flee if they have killed someone accidentally.

12These cities will be places of protection from a dead person’s relatives who want to avenge the death. The slayer must not be put to death before being tried by the community.