sweat of brow
the sweat of (one's) brow
One's own personal efforts or hard work. It's due to the sweat of my father's brow that a barren, fallow little plot of land was transformed into the flourishing farm you see today. This pair of entrepreneurs has created a billion-dollar company by the sweat of their brows.
sweat of (one's) brow
Hard work: landscaped the yard by the sweat of my brow.