Question: Who is the author of these books of Samuel? Response 1: A great many agree in this, that this work was composed, not by one, but by several. Thus Gregory[1] and Athanasius[2] (Sanchez,[3] thus Tostatus,[4] Martyr[5]). Response 2: The first book of Samuel up to chapter 25 (in which Samuel’s death is recounted) Gregory, Theodoret,[6] and Procopius[7] maintain to have been written by Samuel (Lapide,[8] thus Tostatus, Cajetan,[9] Serarius,[10] Vatablus[11] and Lyra[12] in Lapide, Mendoza,[13] Sa[14]). Objection: But in that part the praises of Samuel are everywhere found; which appears foreign to the humility of the saints. See 1 Samuel 2; 3; 12. Responses: 1. Praise seems unbecoming in one’s own mouth, if it be set forth for ostentation; not so, if it be set forth with necessity urging for the glory of God and the edification of men. Thus Job praised himself, Job 29:2, etc. 2. Samuel himself did not publish his own virtues; but rather the Spirit of God, who was speaking in him. God was the author of Scripture, men were only the writers, or rather the pens of the writer (Mendoza). Response 3: The remaining part of the books of Samuel was written by David; thus Isidore,[15] and the rest generally (Tostatus). Objection: With this is inconsistent that little phrase, unto this day, 1 Samuel 27:6; 30:25 (Tostatus). Response: But this phrase was able to have been added by another, after the composition of the book (Lapide). Response 4: The remaining writers of that part were Nathan and Gad. Thus Sixtus Senensis[16] and Bellarmine,[17] out of 1 Chronicles 29:29 (Mendoza, thus Serarius, Lapide, Sanchez). These were to David for record-keepers and secretaries, that they might write his acts day-by-day (Lapide). Response 5: Since those books were written by various men, they were redacted into this order, and digested by another; whether by Jeremiah, who followed the final age of the kings; or by Hezekiah (concerning whom see what things are on Proverbs 25:1); or by Ezra, who both preserved, as many other things, so also the history of the Kings [in the books of Samuel, Kings, and 1 Chronicles] received from others, since it had nearly perished with the city and temple; and brought the confused mass into order (Sanchez).
This is the third book of those that the Hebrews call the Former Prophets, which they inscribe as the first of Samuel, because it treats of him; the Latins, the first of Kings; the Septuagint, the first of Kingdoms. They say that this book was subjoined to the book of Judes, because Eli and Samuel were the two last Judges. Nevertheless, the Hebrews allege other reasons (Vatablus).
[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] Athanasius (c. 298-373) was bishop of Alexandria, and a great defender of Nicean orthodoxy.
[3] Gasper Sanchez (1554-1628) was a Jesuit scholar. He served as Professor of Divinity at Alcala. He wrote Commentarius et Paraphrasis in Libros Regum, as well as commentaries on Isaiah, Jeremiah, and the Song of Solomon.
[4] Alonso Tostado, or Tostatus (c. 1400-1455), was a Spanish, Roman Catholic churchman and scholar. He was trained in philosophy, theology, civil and canon law, Greek, and Hebrew. He wrote commentaries on the historical books of the Old Testament (Genesis-2 Chronicles), and on the Gospel of Matthew.
[5] Peter Martyr Vermigli (1499-1562) began his career as an Augustinian monk, preacher, and lecturer in Italy. Through personal study of the Scripture and the Reformers, he came to embrace the Protestant doctrines. He settled in England and served as Professor of Divinity at Oxford and as Canon of Christ Church. Unhappily, he was forced to flee from England as well, when Mary Tudor took the throne. He settled in Zurich and became Professor of Divinity there. Vermigli wrote In Duos Libros Samuelis Prophetæ Commentarii Doctissimi.
[6] Theodoret (393-457) was bishop of Cyrus, and a significant participant in the Christological controversies of his age. He was an advocate of Antiochian dyophysitism, or moderate Nestorianism, although he condemned the Nestorian affirmation of two Sons in Christ, and the Nestorian denial that Mary was Theotokos, that is, the Mother of God. His orthodoxy was cleared at the Council of Chalcedon (451). With respect to exegetical method, Theodoret came up under the tutelage of Theodore of Mopsuestia and John Chrysostom. He commented on most of the books of the Bible; his comments on the Scripture are sober, and clear in expression.
[7] Procopius (c. 500-c. 560) was a Byzantine historian.
[8] Cornelius à Lapide (1567-1637) was a Flemish Jesuit scholar. His talents were employed in the professorship of Hebrew at Louvain, then at Rome. Although his commentaries (covering the entire Roman Catholic canon, excepting only Job and the Psalms) develop the four-fold sense of Scripture, he emphasizes the literal. His knowledge of Hebrew, Greek, and the commentators that preceded him is noteworthy.
[9] Thomas Cajetan (1469-1534) was an Italian Dominican. He was a theologian of great repute, and a learned proponent of a modified Thomism (Neo-Thomism). Due to his considerable talents, he was made a cardinal. Cajetan proved to be one of the more able opponents of the Reformation. He commented on much of the Old Testament, including the historical books (Joshua-Esther).
[10] Nicholas Serarius (1555-1610) was a Jesuit theologian and exegete. He served as Professor of Theology at the University of Mainz. Commentarius in Librum Josuæ, Judicum, Ruth, Regum, et Paralipomenon.
[11] Francis Vatablus (c. 1485-1547) was a prominent Hebrew scholar, doing much to stimulate Hebraic studies in France. He was appointed to the chair of Hebrew in Paris (1531). Because of some consonance with Lutheran doctrine, his annotations (Annotationes in Vetus et Novum Testamentum), compiled by his auditors, were regarded with the utmost esteem among Protestants, but with a measure of suspicion and concern by Roman Catholics. Consequently, the theologians of Salamanca produced their own edition of Vatablus’ annotations for their revision of the Latin Bible (1584).
[12] Little is known about the early life of Nicholas de Lyra (1270-1340). He entered the Franciscan Order and became a teacher of some repute in Paris. His Postilla in Vetus et Novum Testamentum are remarkable for the time period: Lyra was firmly committed to the literal sense of the text, as a necessary control for allegorical exposition; and he drew heavily upon Hebraic and Rabbinical materials. His commentary was influential among the Reformers.
[13] Francisco de Mendoça (1573-1626) was a Portuguese Jesuit scholar. He wrote Commentaria in Libros Regum.
[14] Manuel de Sa (1530-1596) was a Portuguese Jesuit theologian and exegete. He taught at Coimbra, Gandia, and the Roman College, and wrote Notationes in Totam Scripturam, in which he focuses on the literal sense of the text.
[15] Isidore (c. 560-636) was Archbishop of Seville and a bright and shining light of learning in the intellectual darkness of his age. He presided over the Second Council of Seville (619), which ruled against Arianism, and the Fourth Council of Toledo, which required bishops to establish seminaries in their principal cities.
[16] Sixtus of Siena (1520-1569) converted from Judaism to Roman Catholicism. He was one of the great Dominican scholars of his age, excelling in particular in Biblical scholarship.
[17] Robert Bellarmine (1542-1621) entered the Order of the Jesuits in his late teens. He became one of the great theologians of his era, a Cardinal, and, after his death, a Doctor of the Church.
Here, we have Johann Heinrich Heidegger on the authorship of 1 Samuel: http://www.fromreformationtoreformation.com/post/heidegger-s-bible-handbook-1-samuel-authorship.
John Gill: ' This book, in the Hebrew copies, is commonly called Samuel, or the Book of Samuel; in the Syriac version, the Book of Samuel the Prophet; and in the Arabic version, the Book of Samuel the Prophet, which is the First Book of the Kings; and the Septuagint version, the Book of the Kingdom: it has the name of Samuel, because it contains an history of his life and times; and the Jews say {T. Bab. Bava Bathra, fol. 14. 2.} it was written by him; and as it may well enough be thought to be, to the end of the twenty fourth chapter; and the rest might be written by Nathan and Gad, as may he gathere…