A dagger is a fighting knife with a very sharp point and usually two sharp edges, typically designed or capable of being used as a thrusting or stabbing weapon. Daggers have been used throughout human history for close combat confrontations.
Ehud served as the second judge of Israel following Othniel. He was sent by God to deliver the Israelites from Moabite domination. He is described as being left-handed and a member of the Tribe of Benjamin. He slew Eglon, king of Moab.
Judges 3:16 But Ehud made him a dagger which had two edges, of a cubit length; and he did gird it under his raiment upon his right thigh.
Judges 3:21-22 And Ehud put forth his left hand, and took the dagger from his right thigh, and thrust it into his belly: And the haft also went in after the blade; and the fat closed upon the blade, so that he could not draw the dagger out of his belly; and the dirt came out.