When Israel settled in Canaan and began living in cities, serious crimes such as homicide required legal decisions. Disputes could not be settled by private revenge. They needed judges to decide each case.
The law provided cities of refuge to protect people accused of killing someone. These cities gave safety from immediate revenge and allowed time for a fair trial. The first cities were set apart east of the Jordan River. Later, others were set apart in Canaan (see Numbers 35:9–28).
The laws about these cities appear again in Deuteronomy 19:1–13. They are mentioned here because Moses had just promised long and secure life in the land (4:40). Protecting the innocent from false accusations helped make that promise possible.