The 1649 printed version of the sermon is preceded by a prayer, but it is not included in the manuscript.
Three printings: 1) "Sermon XLIII" in Fifty Sermons, Preached by That Learned and Reverend Divine, John Donne, Dr in Divinity, Late Deane of the Cathedrall Church of S. Pauls London, vol. 2 (London, 1649), pp. 396-411; 2) "Number 4" in George R. Potter and Evelyn M. Simpson, eds., The Sermons of John Donne, vol. 4 (Berkeley and Los Angeles: University of California Press, 1959); 3) "The Anniversary Celebration or our Deliverance from the Powder Treason. Intended for Paul’s Cross, but by reason of the weather, preached in the Church, November 5, 1622. [Lam. 4.20]" in The Oxford Edition of the Sermons of John Donne, vol. 8, ed. Mary Morrissey (Oxford: Oxford University Press, forthcoming).
Donne's sermon on the Anniversary of the Gunpowder Plot in 1622. After he preached the sermon, James I commanded a copy to examine, which appears to be this copy. The sermon was copied down by a scribe, but Donne himself made corrections. This is the only known autograph sermon by Donne. The text in the manuscript has several differences from the printed version of 1649, which are noted in Shami's facsimile edition (1996); see pp. 7, 33-35.
Jeanne Shami; Oxford Edition of the Sermons of John Donne website; Jeanne Shami, ed., John Donne's 1622 Gunpowder Plot Sermon: A Parallel Text Edition (Duquense: Pittsburgh, 1996)