What are these in bright array? J. Montgomery. [All Saints.] Published in his Greenland and other Poems, 1819, p. 185, in 3 stanzas of 8 lines, and headed “Saints in heaven." It was repeated in Cotterill's Selection, 1819, No. 204; in Montgomery's Christian Psalmist, 1825, No. 559; and in his Original Hymns, 1853, No. 237. It is given in several collections in Great Britain and America, and sometimes as, "Who are these in bright array?" In R. Bingham's Hymnologia Christiana Latina, 1871, it is rendered into Latin as "Quid sint cohortes lucidae."
--John Julian, Dictionary of Hymnology (1907)