A bit in the mouth of a horse controls the whole horse. A small rudder on a huge ship in the hands of a skilled captain sets a course in the face of the strongest winds. A word out of your mouth may seem of no account, but it can accomplish nearly anything - or destroy it.
It only takes a spark to set off a forest fire. A careless or wrongly placed word out of your mouth can do that. By our speech, we can ruin the world, turn harmony to chaos, throw mud on reputation, send the whole world up in smoke, and go up in smoke with it, smoke straight from the pit of hell.