The troops eat first.
In earlier times, this was a simple axiom, borne of logic: First came the horses, then the troops (foot soldiers), then the officers. Over time, it was shortened to simply, "the troops eat first."
I would suggest that it's just as relevant today as then, though for different reasons.
In leadership effectiveness, it simply means, "Take care of your people -- especially the good ones -- so they won't have to do it themselves." I often tell C-level managers that "someone has to look after the well-being of your solid performers." If you don't do it yourself, the employee has to. Usually with the help of an outside friend, headhunter, or someone with influence and priorities other than yours.
Make sure they are "fed." Developed, mentored, given ample opportunity. Not necessarily a big, cumbersome, formal effort, but something that clearly shows them that, "Hey, I'm looking out for you -- no need to look elsewhere for development & growth."
The troops eat first, el generale...