Now the acts of David the king, first to last, 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
And he set the Levites at the house of the Lord with cymbals, harps, and lyres according to the commandment of David, and Gad the seer of the king, and Nathan the prophet. For the commandment came from the Lord through His prophets.