An Essay on Criticism l. 525 (1711). The Oxford Dictionary of Proverbs notes, "Although known in Latin (humanum est errare, it is human to err) and in earlier English versions, this saying is generally quoted in Pope's words." The ODP cites "To offend is humaine, to repent diuine" (Henry Wotton, 1578) and "To erre is humane, to repent is divine" (James Howell, 1659).
Homer, Alexander Pope, Gilbert Wakefield (1796). “The Iliad of Homer: Translated by Alexander Pope, Esq. A new edition, with additional notes, critical and illustrative, by Gilbert Wakefield, B.A. ...”, p.259
Alexander Pope (1830). “The Poetical Works of Alexander Pope (including His Translation of Homer). To which is Prefixed the Life of the Author, by Dr. Johnson”, p.233
Alexander Pope (1819). “The Poetical Works of Alexander Pope: In Three Volumes Complete : with His Last Corrections, Additions, and Improvements, Together with All His Notes, as They Were Delivered to the Editor a Little Before His Death : Together with the Commentary and Notes of Mr. Warburton”, p.244