William Galloway, Dictionary of National Biography… (1890)
“ Many of Gray's sermons and communion addresses were taken down at the time of delivery, chiefly in shorthand by his wife, and were published posthumously. Some yet remain in unpublished manuscripts. Pre-Restoration editions are extremely rare, but a few are still extant. The following are the chief editions known: 1. ‘The Mystery of Faith opened up: the Great Salvation and sermons on Death,’ edited by the Revs. R. Trail and J. Stirling, Glasgow, 1659 (in possession of the writer) , and London, 1660, 12mo (Brit. Mus.) ”
