Joshua 20:3

Anyone who kills a person by accident or unintentionally may flee there; they will be for yourselves a refuge from the avenger of blood.

Treasury of Scripture Knowledge

Summary

That the slayer that killeth any person unawares and unwittingly may flee thither: and they shall be your refuge from the avenger of blood.

General references

Bible References

General references

Numbers 35:19
The blood avenger himself will put the killer to death; he must put him to death when meeting him.