Clavis Mystica, a key opening divers mysterious texts of' Scripture.

"Perhaps the most instructive, because most explicit case of the arsmemorativa functioning both as a topic of discussion and structuring principle for homiletic discourse is Daniel Featley's Clavis Mystica (1636). Featley served as chaplain to Charles I. Although his sermons are by no means the apogee of the genre, his work exemplifies the commonplace attitude toward the interplay of mnemonic emblems and admonitory sermons in the seventeenth century" (www.biblicalcyclopedia.com)

"Daniel Featley was educated as a chorister of Magdalen College. He was admitted scholar of Corpus Christi College 13 Dec. 1594, and probationer fellow 20 Sept. 1602. having taken his B.A. degree 13 Feb. 1601. He proceeded M.A. 17 April 1606, and became noted as a disputant and preacher. In 1607 he delivered an oration at the funeral of John Rainolds, president of Corpus, his godfather and benefactor. In 1610 and the two following years he was in attendance as chaplain upon Sir Thomas Edmondes [q. v.], the English ambassador at Paris, and was noticed for his fearless attacks upon the Roman Catholic doctrines and his disputations with the Jesuits." (DNB)