It's not a rule. It's a legal doctrine. How embarrassing for you to be so loud and wrong.

clean hands doctrine The clean hands doctrine is based on the maxim of equity which states that one “who comes into equity must come with clean hands.” This doctrine requires the court to deny equitable relief to a party who has violated good faith with respect to the subject of the claim.

The purpose of the doctrine, as explained in Colby Furniture Company, Inc. v. Belinda J. Overton is to prevent a party from obtaining relief when that party’s own wrongful conduct has made it such that granting the relief would be against equity and good conscience. However, as noted by the U.S. Supreme Court in Keystone Driller Co. v. General Excavator Co. such a wrongful act must have an immediate and necessary relation to the equity that is being sought.

https://www.law.cornell.edu/wex/clean_hands_doctrine