Authors:

Don't bite the hand that has your allowance in it.

Paul Dickson (2014). “The Official Rules: 5,427 Laws, Principles, and Axioms to Help You Cope with Crises, Deadlines, Bad Luck, Rude Behavior, Red Tape, and Attacks by Inanimate Objects”, p.36, Courier Corporation
Don't bite the hand that has your allowance in it.