A good fox does not eat his neighbor’s chickens.
More French Proverbs:
All the keys do not hang at one girdle.French
What is enough was never little.
French
Who draws his sword against his prince must throw away his scabbard.
French
You do not fatten pigs with pure water.
French
When the door is low one must stoop.
French
One never gets more than one's money's worth of anything.
French