E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
He who trembles to hear a leaf fall should keep out of the wood. This is a French proverb: Qui a peur de feuilles, ne doit aller au bois. Our corresponding English proverb is, He who fears scars shouldnt go the wars. The timid should not voluntarily expose themselves to danger.