Deuteronomy 4:42

42that athe manslayer might flee there, anyone who kills his neighbor unintentionally, without being at enmity with him in time past; he may flee to one of these cities and save his life:

Deuteronomy 19:6

6lest bthe avenger of blood in hot anger pursue the manslayer and overtake him, because the way is long, and strike him fatally, though the man did not deserve to die, since he had not hated his neighbor in the past.
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