O God unseen, yet ever near. E. Osler. [Holy Communion.] First published in Hall's Mitre Hymn Book, 1836, No. 270, in 4 stanzas of 4 lines, and entitled, "Spiritual Food." In the March number of Osler's Church and King, 1887, it was repeated with the single change of stanza iv., l. 1., from "Thus may we all" to "Thus would we all," &c. In some collections, as the English Hymnal, 1856 and 1861, it is given as, “O Christ unseen, yet ever near"; and in others as, "O God unseen, yet truly near." Other corruptions of the text are also found in Darling's Hymns, 1887, and other collections. Hymns Ancient & Modern is an exception in favour of the original, with the single change in stanza iv., l.1, of " Thy words" to "Thy word," The use of this hymn in a more or less correct form is very extensive in all English-speaking countries.
--John Julian, Dictionary of Hymnology (1907)
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. This hymn, in 3 stanzas of 4 lines, was given in Longfellow and Johnson's Hymns of the Spirit, 1864, as No. 44, and entitled "At the Fountain." In the index it is signed Anon. It is, in fact, E. Osier's hymn in a rewritten form, 7 of its 12 lines being direct from Osier (see p. 833, i.). In modern American collections it begins "O God unseen, but ever near," and is expanded into 16 lines, the increase being attributed to S. Longfellow. This form is in several American hymnbooks, including The Pilgrim Hymnal, 1904.
--John Julian, Dictionary of Hymnology, New Supplement (1907)