Time, the subtle thief of youth. — John Milton

Milton, John. "Sonnet VII (How Soon Hath Time)." Milton: The Complete Poems, edited by John Leonard. Penguin, 1992, I. 1.

Milton, John. Poems of Mr. John Milton both English and Latin, compos'd at several times. London: Humphrey Moseley, 1645, sonnet 7, I. 1.