One who cuts off his own feet, and one who drinks violence,
is a person who sends messages by the hand of a fool. Bible see other translations

“One who cuts off his own feet.” This proverb warns about trusting a fool to do important work. If you chop off your own feet, you cannot deliver a message, but that is in effect what happens when you give the message to a fool—it will not arrive. And even if it does arrive, it will be so mangled that it will cause harm instead of being helpful. Also, the meaning of the phrase “drinks violence” is that the person who has sent the fool is hurting himself. The phrase is referring to what happens to the person who sends a message via a fool: the message gets lost or misinterpreted and that leads to violence for the one who sent the fool. Sending a message via a fool is a self-destructive action and the sender becomes the injured party when the fool turns out to be unreliable.

Commentary for: Proverbs 26:6