Numbers 35 & 36

And the Lord spoke to Moses, saying, “Speak to the people of Israel and say to them, When you cross the Jordan into the land of Canaan, then you shall select cities to be cities of refuge for you, that the manslayer who kills any person without intent may flee there.  The cities shall be for you a refuge from the avenger, that the manslayer may not die until he stands before the congregation for judgment. – Numbers 35:9-12

Passage: Numbers 35