Meaning: The curse of manual labor.
Genesis 3:19
In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return.
"It is not necessary that a man should earn his living by the sweat of his brow unless he sweats easier than I do."
Henry David Thoreau (1854) Walden