Deuteronomy 19:6
Lest the avenger of the blood pursue the slayer, while his heart is hot, and overtake him, because the way is long, and slay him; whereas he was not worthy of death, inasmuch as he hated him not in time past. Lest the avenger of the blood pursue the slayer, while his heart is hot, and overtake him, because the way is long, and slay him; whereas he was not worthy of death, inasmuch as he hated him not in time past.
The verse stands in the fifth and last book of the Pentateuch, in the three addresses given by Moses just before his death, in chapters 5 to 26 reviewing the law for the new generation, the second-law section that gives the book its name, with Deuteronomy meaning second law or duplicate of the law, specifically within chapters 18 to 21. It belongs to the laws concerning murder recalled before Israel crossed the Jordan, as part of God's sacred law which Israel was solemnly bound to keep.
The cities of refuge gave a person who had caused a death a place to escape the avenger and claim a fair trial, mitigating the established custom that the victim's next of kin avenge the death by killing the person responsible. The unintentional killer could thus receive a fair trial before punishment rather than be slain in private vengeance by a relative acting from personal malice, because protection from the blood avenger's hot pursuit was due to one not guilty of deliberate murder.
The verse uses soul to mean the person, for the Hebrew word nephesh, translated him for the pursued slayer, means the man himself as a person and gives the idea of personality just as clearly as where nephesh is translated person or soul. The phrase rendered slay him literally means smite his soul and refers to the accidental killer whom the blood avenger might overtake and kill.
The verse protects one who killed unintentionally from being pursued, overtaken and killed by the blood avenger while his heart is hot with anger and enraged before the case could be judged. The long way to safety could give the avenger time to catch the fugitive, which is why a nearby refuge was needed. It distinguishes accidental killing from murder and restricts blood revenge, since the slayer was not worthy of death or liable to death because he had not hated the victim in time past and was not guilty of deliberate murder.
The elders' decision at the city gate admitted the fugitive temporarily, and a regular trial before a higher court would follow once witnesses and accusers could appear.
God's provision of a city of refuge for one fleeing bitter pursuit though not worthy of death means that Jews who accept Christ and are most bitterly persecuted and must leave their countrymen are to be given such a refuge. It is to be a place secured for them where they find safety and work and at the same time are trained to be workers for others.