The 3 Wooden Plaques

[Hobie Hartkins]

I'm sure I've asked before but I can't find it, but what were the 3 wooden plaques in Boss' office at the Boor's Nest?

1. One bad turn deserves another

2. Do unto others before they do it unto you.

3. ???????  *

 

* I'd appreciate any help finding  the  3rd one and if you know it, the episode that shows it. I asked a long time ago and thought later on, I'll find it but never have.