Gad was a seer or prophet mentioned in the Hebrew Bible and the writings of Jewish historian Josephus. He was one of the personal prophets of King David of Israel and, according to the Talmudic tradition, some of his writings are believed to be included in the Books of Samuel. He is first mentioned in 1 Samuel 22:5 telling David to return from refuge in Moab to the forest of Hereth in the land of Judah.
The next Biblical reference to Gad is 2 Samuel 24:11-13 where, after David confesses his sin of taking a census of the people of Israel and Judah, God sends Gad to David to offer him his choice of three forms of punishment.
Gad is mentioned a last time in the Books of Samuel in 2 Samuel 24:18, coming to David and telling him to build an altar to God after God stops the plague that David chose as punishment. The place indicated by Gad for the altar is "in the threshing-floor of Araunah the Jebusite."