Numbers 35:13-15 Modern English Version (MEV)
13 The cities which you designate shall be your six cities of refuge. 14 You will give three cities across the Jordan, and three cities you will give in the land of Canaan, which will be cities of refuge. 15 For the children of Israel, and for the stranger, and for the foreign sojourner among them will be six cities. These will be for a refuge. Everyone that unintentionally kills any person may flee there.