It is not enough to tell me you worked hard to get your gold.  So does the Devil work hard.

Henry David Thoreau (1817-1862) American philosopher and writer

Essay (1863-10), “Life without Principle,” Atlantic Monthly, No. 72
    (Source)

Writing of the California Gold Rush.

Based his lecture (1854-12-06) "What Shall It Profit?" Railroad Hall, Providence, Rhode Island. He had edited it for publication before his death, and it was published posthumously.