Proverbs 26:18

18 Someone who tricks someone else and then claims that he was only joking is like a crazy person playing with a deadly weapon.

Proverbs 26:18 In-Context

16 A lazy person will think he is smarter than seven men who can give good reasons for their opinions.
17 Getting involved in an argument that is none of your business is like going down the street and grabbing a dog by the ears.
18 Someone who tricks someone else and then claims that he was only joking is like a crazy person playing with a deadly weapon.
20 Without wood, a fire goes out; without gossip, quarreling stops.
Scripture taken from the Good News Translation - Second Edition, Copyright 1992 by American Bible Society. Used by Permission.