Deuteronomy 19 describes the cities of refuge, places that Israelites could flee after accidentally killing someone. There were initially 3 cities designated on the west side of the Jordan (Bezer, Ramoth-Gilead and Golan). After Israel conquered the Canaanites on the east side of the Jordan, 3 more cities were assigned as cities of refuge (Hebron, Shechem and Kedesh). These are listed in Joshua 20v7-8.
The cities of refuge provided protection, but only under specific circumstances. The accidental murderer had to flee immediately, since relatives of the now dead person could pursue them and avenge the death at any time that the accidental murderer was outside the city of refuge. This process is a shadow of salvation offered through the sacrifice of Christ. There is a specific method (“no other name under heaven given among men by which we must be saved”), and we are to remain in Christ for our whole lives. Through Christ, God offers grace and mercy that the Law did not – God is not waiting outside to murder us when we sin and temporarily leave the covering of Christ.
In Acts 10, Peter explains to Cornelius the incredible covering offered through Christ. “God anointed Jesus of Nazareth with the Holy Spirit and with power… to him all the prophets bear witness that everyone who believes in him receives forgiveness of sins through his name”. Peter also explains that this incredible gift is available to all, “God shows no partiality, but in every nation anyone who fears him and does what is right is acceptable to him”. What an amazing God we serve!