Numbers 35:11
designate cities to serve as your cities of refuge, so that a person who kills someone unintentionally may flee there.

Exodus 21:13
But if he did not lie in wait, but God allowed it to happen, then I will appoint for you a place where he may flee.

Deuteronomy 19:5
If he goes into the forest with his neighbor to cut timber and swings his ax to chop down a tree, but the blade flies off the handle and strikes and kills his neighbor, he may flee to one of these cities to save his life.

Joshua 20:3, 5
so that anyone who kills another unintentionally or accidentally may flee there. These will be your refuge from the avenger of blood. . . .