John Gills Exposition of the Bible Commentary - Joshua 20:3
That the slayer that killeth any person unawares, and unwittingly, may flee thither ,.... Who through mere accident, and without design, killed a person, friend or foe, one of his own kindred, or a stranger, without any malice against him, or intention to take away his life: and they shall be your refuge from the avenger of blood ; from any of the relations of the deceased, who might be stirred up to avenge the blood of his kinsman on the slayer; see Numbers 35:12 . read more
Matthew Henry's Complete Commentary - Joshua 20:1-6
Many things were by the law of Moses ordered to be done when they came to Canaan and this among the rest, the appointing of sanctuaries for the protecting of those that were guilty of casual murder, which was a privilege to all Israel, since no man could be sure but some time or other it might be his own case; and it was for the interest of the land that the blood of an innocent person, whose hand only was guilty but not his heart, should not be shed, no, not by the avenger of blood: of this... read more