The book of Gad the seer is an ancient record of King David’s life and reign mentioned in 1 Chronicles 29:29: “Now the acts of King David, first and last, indeed they are written in the book of Samuel the seer, in the book of Nathan the prophet, and in the book of Gad the seer” (NKJV). The book of Gad the seer was apparently written by Gad, a prophet who ministered during David’s life. Other translations name it “The Record of Gad the Seer” (NLT) or “the Chronicles of Gad the seer” (ESV).
It was common for ancient kings to keep annals of their royal activities, and ancient prophets sometimes played a role in the compilation of these records or provided a divine perspective on historical events. Sections of Jeremiah and Isaiah provide examples of prophetic historical narrative, though the records kept by Gad may have been more straightforward and procedural. Either way, the chronicler knew of Gad’s work, commended it to his readers, and likely drew on it himself in the composition of 1 and 2 Chronicles. The biblical books of Kings and Chronicles reference numerous historical sources, citing them for support and using them to fill in gaps left by their selective narrative (1 Kings 11:41; 15:31; 2 Chronicles 13:22).
The Cochin Jews in India possessed a pseudepigraphal work claiming to be written by Gad the seer, which was discovered in the 18th century. There is only one extant, relatively recent copy of this interesting manuscript, currently housed at the University of Cambridge. It contains supposed visions from God and stories about David and the people around him. Its original date of composition is a matter of debate, but the most common alternatives are either the first few centuries AD or the Middle Ages.
The real book of Gad the seer is currently lost and will probably remain lost. The chronicler’s reference to other sources points to the historical authenticity of 1 and 2 Chronicles and should give Christians even greater confidence in the factual nature of the Old Testament. As John Thompson, an Old Testament scholar, concludes regarding 1 Chronicles 29:29, “The use of written records preserved by Samuel, Nathan the prophet, and Gad the seer may be a reference to material now found in the canonical books of Samuel and Kings. Whether or not that is the case, the point here is that the facts to which Chronicles bears witness are well attested and that in fact David did much more than is written here” (1 and 2 Chronicles, Broadman & Holman Publishers, 1994, p. 200).