by the sweat of one's brow

What is the origin of the idiom "by the sweat of one's brow" and when to use it?

The idiom "by the sweat of one's brow" originates from the Bible, specifically from the Book of Genesis. In the biblical narrative, after Adam and Eve were expelled from the Garden of Eden due to their disobedience, God declared to Adam that he would have to work the land and earn his sustenance through toil and labor. The phrase figuratively captures the idea that one's livelihood and success are achieved through hard work, physical labor, and exertion. It is commonly used in discussions related to work, productivity, and achievements. The phrase is often used to describe the exertion of physical or mental effort required to succeed or earn a living.