The Book of Gad the Seer, also called The Word of Gad the Seer, is said to have been written by the Prophet mentioned in 1 Chronicles 29:29. The passage reads: "Now the acts of David the king, first and last, behold, they are written in the book of Samuel the seer, and in the book of Nathan the prophet, and in The Book of Gad the Seer."
The prophet, Nathan and the seer, Gad, lived at the same time under the reign of King David. Therefore, this little book gives us fresh insight into the Jewish world of that time. King David was the third king of the United Kingdom of Israel. He lived and ruled around 1000 BC. Thus, if the book was actually written by Gad, its origin would date back to that time.
The original manuscript was believed by the Black Jews of Cochin of India to be an authentic and sacred manuscript. The Cochin Jews (also known as Malabar Jews or Kochinim Jews) are the oldest group of Jews in India, with roots that are said to date back to the time of King Solomon.