10-13. David's heart smote him after that he had numbered the people. And David said unto the Lord, I have sinned—The act of numbering the people was not in itself sinful; for Moses did it by the express authority of God. But David acted not only independently of such order or sanction, but from motives unworthy of the delegated king of Israel; from pride and vainglory; from self-confidence and distrust of God; and, above all, from ambitious designs of conquest, in furtherance of which he was determined to force the people into military service, and to ascertain whether he could muster an army sufficient for the magnitude of the enterprises he contemplated. It was a breach of the constitution, an infringement of the liberties of the people, and opposed to that divine policy which required that Israel should continue a separate people. His eyes were not opened to the heinousness of his sin till God had spoken unto him by His commissioned prophet.

     9. the Lord spake unto Gad, David's seer—Although David was himself endowed with a prophetic gift, yet, in matters relating to himself or his kingdom, he was in the habit of consulting the Lord through the medium of the priests; and when he failed to do so, a prophet was sent on extraordinary occasions to admonish or chastise him. Gad, a private friend, was occasionally employed as the bearer of these prophetic messages.