Fain would I, Lord of grace. Lent. This in the Supplemental Hymns to Hymns Ancient & Modern, 1889, is a translation by Jackson Mason, of a "Miserere" from a Greek Canon in the Parakletike for a Sunday Evening. Mr. Moorsom gives the Greek text in his Historical Companion to Hymns Ancient & Modern, 1889, p. 87, from a copy of the Triodion, ed. 1886, pp. 438-440. It is by an unknown author of the 6th or 7th century.
--John Julian, Dictionary of Hymnology, Appendix, Part II (1907)