From the fruit of his mouth a man eats what is good, but the soul of the treacherous gets violence.
Proverbs 13:2

This isn't literally about eating, but about all that a person does. Speaking good things, giving good advice, using your voice to bring glory to God will bring good things back to you. Good relationships, good reputation, etc.

Our interaction with the world is a positive feedback loop. If we seek out wise and righteous inputs and then reflect those things back into the world, more of them come back to us again.