Judges 3:14-16

So the children of Israel served Eglon king of Moab eighteen years. But when the children of Israel cried out to the LORD, the LORD raised up a deliverer for them: Ehud the son of Gera, the Benjamite, a left-handed man. By him the children of Israel sent tribute to Eglon king of Moab. Now Ehud made himself a dagger (it was double-edged and a cubit in length) and fastened it under his clothes on his right thigh.