Sweet as the Shepherd's tuneful reed. W. Shirley. [Spring.] Published in The Collection of Hymns sung in the Countess of Huntingdon's Chapels, Bath, W. Gye, N. D. (circa 1773), No. 86, in 4 stanzas of 6 lines. In common with all the hymns in that Collection it is anonymous; but in the Life of the Countess, 1839, vol. ii. p. 291, it is definitely stated to be by W. Shirley. The most widely known form of this hymn begins with stanzas ii., "Peace, troubled soul, whose plaintive moan." It is composed of stanzas ii., iii., and appeared in the American Prayer Book Collection, 1826, No. 130. It is repeated in several American hymn-books.
-- John Julian, Dictionary of Hymnology (1907)