Judges 3:16

‘ And Ehud made himself a sword which had two edges, of a cubit length, and he slung it under his clothing on his right thigh.'

The short sword he made for himself was between one foot (thirty centimetres) and one foot six (forty five centimetres) in length, depending whether it means the short cubit or the long cubit. It was double-edged. He hid it under his clothing and because he was left-handed it was slung at his right side. It was made so that it could be more easily concealed than a normal sword, but be long enough to pierce the over-fat king to the heart. It was all carefully planned.