David in spelunca Engaddi (âÂÂDavid in the Cave of EngediâÂÂ) is a 1795 oratorio by Simon Mayr. The librettist is unknown, but is possibly Giuseppe Maria Foppa who supplied the Latin texts for Iacob a Labano fugiens (1791), Sisara (1793), and Tobiae matrimonium (1794).