In the law given to the ancient Hebrew nation the deadly seriousness of negligence was deeply impressed upon the people. If a man accidentally killed another​—for example, if his axhead flew off and struck a man working with him—​the one causing the accident had to flee immediately to one of six cities set apart in the land, called “cities of refuge.” There he would receive temporary sanctuary. Then a trial was held, and if the court found the incident to be truly accidental, the unintentional manslayer was required to live within the boundaries of the city of refuge until the death of the nation’s high priest, which might be many years.​—Num. 35:11-13, 22-25.

Moreover, the careless person can become bloodguilty, just as the unintentional manslayer in ancient Israel who accidentally caused a death. Though such a person was not a murderer, he was bloodguilty. Life was sacred, and he had to remain in the refuge city. To leave it would show unconcern for life and for God’s law as to the sanctity of life. He would show that he was not sorry for the death that he had caused, and would himself be deserving of death.