The format of the text is based in a similar format to that found in some Celtic Christian prayers and songs, such as those found in the Christian-era Scottish Gaelic collection, the Carmina Gadelica. Rutter has said that his English-only composition is based on "an old Gaelic rune", and that he added a line mentioning Jesus and the word Amen, to make it also a Christian anthem. However, most surviving prayers with this structure, in both Gaelic and English, already include Christian elements. The original, English-language piece that the central lines of Rutter's piece are directly excerpted from, published in the 1895 novel, "The Dominion of Dreams: Under the Dark Star", by Celtic Revival writer William Sharp / Fiona Macleod, while not containing the words "Jesus," or "Amen," does mention both "the Son of Peace" and "the heart of Mary," along with other Christian imagery.