If you hate something, refrain from doing it to anybody else. Do you hate it when somebody speaks ill of you? Then speak no ill of any person. Do you hate it when somebody makes false accusations against you? Then do not accuse anybody falsely. Do you hate it if somebody sets you at naught or insults you or makes off with what is yours or [does] whatever is like that? Then do nothing of that sort to another. For the person who can keep this saying, it will suffice for his salvation.
–The Desert Fathers (and Mothers)