en_tn_condensed/2sa/20/08.md

When they were

"When Joab and the men of Judah were"

belt

a strip of leather or other material used to hold clothing or weapons in place

sheathed sword

This means the sword was in its protective covering.

the sword fell out

Joab let the sword fall out to fool Amasa into thinking that he Joab was unarmed, so that Amasa would allow him to walk closer to him. Alternate translation: "he allowed the sword to fall on the ground so Amasa would think he was unarmed" (See: rc://en/ta/man/jit/figs-explicit)