O mighty Mother! why that light? F. W. Faber. [Whitsuntide.] Published in his Jesus and Mary, &c, 1849, in 21 stanzas of 4 lines on "The Descent of the Holy Ghost." Also in his Hymns, 1862. The hymn, "He comes, He comes, the Holy One," in the Sarum Hymnal, 1868, is compiled from the 1849 text.
--John Julian, Dictionary of Hymnology (1907)