Leviticus 14:9

These were the cities appointed for all the children of Israel, literally, "the cities of appointment," and for the stranger that sojourneth among them, that whosoever killeth any person at unawares might flee thither, and not die by the hand of the avenger of blood, until he stood before the congregation and thus had the opportunity of proving the absence of any evil intention in the slaying which had happened. The entire chapter testifies to the grace and mercy of the Lord. We Christians learn here that even sins that are done unintentionally, unwittingly, are nevertheless transgressions of God's holy Law, just as is the inherited tendency to all sins which we bear in our hearts. But God has placed before us the true city of refuge, in the Gospel of Jesus Christ. Every one who flees to the Redeemer and His mercy, relying upon His atonement alone, will in no wise be cast out.