The story of Ehud and Eglon is one of the most vulgar stories in the Book of Judges—a history of the Israelites from before they had a king, and were (kind of) governed by a series of judges.
The Israelites had turned away from God. So God had allowed Eglon, the king of the Moabites, to conquer Israel. But after eighteen years of subjugation, the Israelites turn back to God and He raises up a deliverer, called Ehud*. What’s special about Ehud? He’s left-handed. Yep.
Ehud makes himself a short, easily-concealable sword, and, being left-handed, hides it on his right thigh. Weapons are usually kept on the left side (so the right hand can access them), so Ehud’s blade is far less likely to be discovered.
Ehud then pays a visit to King Eglon, bringing a stack of tribute with him. After paying his respects, he tells the king he has something secret to discuss, and so the king dismisses his attendants.
At this moment, Ehud (left-handedly) draws his sword, pulling out a totally action-movie one-liner with it:
“I have a message from God for you!” he proclaims as he plunges the sword into the king’s abdomen.
This is where it gets a bit grisly.
Eglon is so fat that the hilt goes in after the blade. Ehud’s sword is completely irretrievable. And the king’s bowels discharge. Great.
Ehud locks the door from the inside and escapes through the latrine. The attendants, noticing that the door is locked, assume the king is draining his bladder inside and choose to leave him alone. After waiting awhile, though, they grow concerned, and find the key to the door, only to find their monarch lying dead in a pool of his own…
But by now, Ehud has a head-start. Upon returning home, he uses the death of the occupying king to rally the Israelite army. They defeat the Moabite army utterly and reclaim their land, and there’s peace for the next eighty years.
I guess the moral of the story is that even left-handed people can sometimes be useful.