Never put your finger between the tree and the bark.
More French Proverbs:
It is a wise man who lives with money in the bank, it is a fool who dies that way.French
He who has much, wants more.
French
A little pack serves a little pedlar.
French
The wise do as much as they should, not as much as they can.
French
No sauce like appetite.
French
He who hold the thread holds the ball.
French