en_tn_lite_do_not_use/jos/20/09.md

would not die by the hand of the avenger

Here "by the hand" is an idiom that means to be the specific cause of something. Alternate translation: "would not be killed by the avenger" (See: rc://en/ta/man/jit/figs-idiom)

the avenger of blood

This was a relative of the person who had been killed. His job was to kill the person who had killed his relative.

blood

Blood is a metonym for the death of the person whose blood has been shed. See how you translated this in Joshua 20:3. Alternate translation: "death" (See: rc://en/ta/man/jit/figs-metonymy)