Note 42 — BOOK I.
John Sharpe translation
St. Germanus drew up a body of his new converts in a valley surrounded on every side by mountains, and, on the approach of their enemies, ordered that on a given signal, all should shout “Hallelujah.” The sudden sound, being reverberated by the surrounding mountains, struck their foes with such a panic, that they instantly fled. See Bede, Hist. Eccl. b. i. c. 20.