Cross reference
Numbers 35:22
22 But if he thrust him suddenly without enmity, or hurled on him anything without lying in wait,
Exodus 21:13
13 but not if it is unintentional, but God allows it to happen: then I will appoint you a place where he shall flee.
Numbers 35:11
11 then you shall appoint you cities to be cities of refuge for you, that the manslayer who kills any person unwittingly may flee there.
Deuteronomy 19:5
5 as when a man goes into the forest with his neighbor to hew wood, and his hand fetches a stroke with the axe to cut down the tree, and the head slips from the handle, and lights on his neighbor, so that he dies; he shall flee to one of these cities and live:
Joshua 20:3
3 that the manslayer who kills any person unwittingly [and] unawares may flee there: and they shall be to you for a refuge from the avenger of blood.
Joshua 20:5
5 If the avenger of blood pursue after him, then they shall not deliver up the manslayer into his hand; because he struck his neighbor unawares, and didn't hate him before.