The Torah establishes six cities of refuge, three on each side of the Jordan River, as places where a person who has killed another unintentionally could flee for protection from the victim's family before any trial had established whether the killing was accidental or deliberate. Numbers 35, Deuteronomy 19 and Joshua 20 together set out the institution: the cities were to be Levitical cities, accessible by well maintained roads, and a person who reached one and was found by the elders there to have killed without premeditation or malice could remain in safety, while a person credibly accused of intentional murder could be extradited from the city for trial and, if convicted, executed.
The law draws a sharp legal distinction, unusual for its ancient Near Eastern context, between accidental killing and murder, treating the two as requiring different legal consequences rather than the blood price or retaliation that governed killing in many neighboring legal traditions, and the cities of refuge functioned as the practical institution giving that legal distinction real protective force. The named cities, Kedesh, Shechem and Hebron west of the Jordan and Bezer, Ramoth and Golan east of it, were chosen in part for their spread across the land so that no manslayer would face an impossibly long flight to reach protection.