Deuteronomy 4:40-42

Amplified Bible

⁴⁰ So you shall keep His statutes and His commandments which I am commanding you today, so that it may go well with you and with your children after you, and so that you may live long on the land which the Lord your God is giving you for all time.”

⁴¹ Then Moses set apart three cities [of refuge] beyond the Jordan toward the rising of the sun (eastward), ⁴² so that someone who committed manslaughter could flee there, [that is, a person] who killed his neighbor unintentionally and without previously having hostility toward him, and that by escaping to one of these cities he might [claim the right of asylum and] save his life: