en_tn/1ch/10/05.md

fell on his sword

He probably stuck the handle into the ground and leaned on the point so the sword would go through his body as he fell down. The action is a metonym for the result, death. See how you translated this in 1 Chronicles 10:4. AT: "killed himself with his sword" (See: rc://en/ta/man/translate/figs-metonymy)