John Milton (1824). “The Poetical Works of John Milton: With Notes of Various Authors, Principally from the Editions of Thomas Newton, Charles Dunster and Thomas Warton ; to which is Prefixed Newton's Life of Milton”, p.213
Letter to Shelley, August 1820, in H. E. Rollins (ed.) 'The Letters of John Keats' (1958) vol. 2, p. 323; echoing Edmund Spenser 'The Faerie Queen' (1596) bk. 2, canto 7, st. 28, l. 5: 'And with rich metal loaded every rift'