Don’t shut the barn door after the horse is stolen.
More French Proverbs:
The little alms are the good alms.French
Feather by feather the goose can be plucked.
French
It is well to leave off playing when the game is at its best.
French
Fools go in throngs.
French
All is luck or ill luck in this world.
French
There are no miracles for those that have no faith in them.
French