sweat of (someone's) brow

Translations
потом (чьего-либо) лба
He built his business with the sweat of his brow.
Он построил свой бизнес потом своего лба.
Definitions
An expression referring to the hard work, effort, or labor that someone puts into accomplishing something; it emphasizes that the results or rewards are achieved through personal toil and diligence.