Heidegger's Bible Handbook: 1 Samuel: Authorship

2. Was the author of the book, Samuel, David, Jeremiah, Ezra, or some other.

With respect to the author of these books, most agree that they were written, not by one, but by several. And, that the first book to chapter 25, in which the death of Samuel is related, was written by Samuel himself, Gregory the Great,[1] Theodoret, and Procopius assert: but not without reason do other doubt concerning this, which appears, they suppose, to be foreign to the humility of the sacred writers. And what Isidore and others teach, that the remaining part was written by David, is uncertain, which διαῤῥήδην/expressly was not able to be done by him, from that little phrase, unto this day, 1 Samuel 27:6; 30:24, 25, as Torniellus[2] argues. Perhaps he would not err, who out of 1 Chronicles 29:29 would conclude, that Samuel composed the Annals of the matters conducted under Eli and his government, and that Nathan and Gad of the matters occurring under the Kingdom of Saul and David: and that afterwards a θεόπνευστον/inspired man, whether he be Jeremiah, who followed the last age of the Kings, or Ezra, who preserved, as a great number of other things, so also the history of Kings devised by others; reduced that into the order and scheme that is seen today.

[1] Gregory the Great (c. 550-604) was elected Pope in 590. He was a monk, scholar, prolific author, and, having been made pope, instrumental in reinvigorating the missionary work of the Church. [2] Augustine Torniellus (1543-1622) was a member of the Society of Barnabites, a Counter-Reformation order. His work, Annales Sacri et Profani, cleared up many geographical and chronological difficulties and obscurities, especially in the Old Testament.