Charles Ellicott Commentary Judges 19:29

"And when he was come into his house, he took a knife, and laid hold on his concubine, and divided her, limb by limb, into twelve pieces, and sent her throughout all the borders of Israel." — Judges 19:29 (ASV)

Divided her. —We see again that the narrative is taking us back to wild times, when the passions of men expressed themselves in wild and fierce expedients. A similar method of arousing a nation, but different in its details, is narrated in 1 Samuel 11:7, when Saul sends around the pieces of an ox, as was done by the ancient Scythians (Lucian, Toxaris, chapter 48). Many analogous customs existed among the ancient Highlanders and have been repeated even in recent days among the Arab tribes (Stanley, i. 301).

With her bones. —Literally, according to her bone.

Into twelve pieces. —One for each tribe. Benjamin was probably appealed to in this way, as well as the other tribes. It is needless to suppose that one was sent to Eastern Manasseh or to Levi.