At the Lamb's High Feast we sing. By R. Campbell, written in 1849 [C. MSS.], and first printed in his collection commonly known as the St. Andrew's Hymnal, 1850, in 4 stanzas of 8 lines. In the original manuscripts the first two lines are added as a refrain to each verse, but are omitted in the printed text. Cooke and Denton's Hymnal was the first to bring it into prominent notice, although in an altered form which has been copied by many compilers. Its use exceeds that of all other translations of the "Ad Regias Agni" put together; being found in a more or less correct form, in the most important collections of the Church of England. Many of the alterations in Hymns Ancient & Modern, Church Hymns, Thring, and others date from Cooke and Denton's Hymnal, 1853, the Salisbury Hymn Book 1857, and others. Another arrangement of Campbell's text is, "To the Lamb's High Feast we press" given in Rev. Francis Pott's Collection, 1861, No. 90.
-- John Julian, Dictionary of Hymnology (1907)