to be a certainty, to be clear

you can't judge a book by its cover (it is not possible nor advisable to judge things by external appearances alone)

money doesn't grow on trees

God hates a coward; nothing ventured, nothing gained; no pain, no gain

Alternative form of qui ne risque rien n'a rien

money can't buy happiness

(intransitive, figuratively, informal) not to embarrass oneself with manners, be indelicate

(transitive, informal, figuratively) to be sick of (something/someone), not to be able to stand the sight of (something/someone) anymore

(informal, figuratively) to feel under the weather, to feel fragile

(figuratively, informal) Synonym of ne pas avoir inventé le fil à couper le beurre