A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
2 Kings (2 Samuel) 24:1
sa2 24:1DAVID NUMBERS THE PEOPLE. (Sa2 24:1-9)
again the anger of the Lord was kindled against Israel, and he moved David against them to say, Go, number Israel and Judah--"Again" carries us back to the former tokens of His wrath in the three years' famine [Sa2 21:1]. God, though He cannot tempt any man (Jam 1:13), is frequently described in Scripture as doing what He merely permits to be done; and so, in this case, He permitted Satan to tempt David. Satan was the active mover, while God only withdrew His supporting grace, and the great tempter prevailed against the king. (See Exo 7:13; Sa1 26:19; Sa2 16:10; Psa 105:25; Isa 7:17, &c.). The order was given to Joab, who, though not generally restrained by religious scruples, did not fail to present, in strong terms (see on Ch1 21:3), the sin and danger of this measure. He used every argument to dissuade the king from his purpose. The sacred history has not mentioned the objections which he and other distinguished officers urged against it in the council of David. But it expressly states that they were all overruled by the inflexible resolution of the king.
2 Kings (2 Samuel) 24:5
sa2 24:5they passed over Jordan--This census was taken first in the eastern parts of the Hebrew kingdom; and it would seem that Joab was accompanied by a military force, either to aid in this troublesome work, or to overawe the people who might display reluctance or opposition.
the river of Gad--"Wady" would be a better term. It extends over a course estimated at about sixty miles, which, though in summer almost constantly dry, exhibits very evident traces of being swept over by an impetuous torrent in winter (see Deu 2:36).
2 Kings (2 Samuel) 24:6
sa2 24:6the land of Tahtim-hodshi--that is, the land lately acquired; namely, that of the Hagarites conquered by Saul (Ch1 5:10). The progress was northward. Thence they crossed the country, and, proceeding along the western coast to the southern extremities of the country, they at length arrived in Jerusalem, having completed the enumeration of the whole kingdom in the space of nine months and twenty days.
2 Kings (2 Samuel) 24:9
sa2 24:9Joab gave up the sum of the number of the people unto the king--The amount here stated, compared with Ch1 21:5, gives a difference of three hundred thousand. The discrepancy is only apparent, and admits of an easy reconciliation; thus (see Ch1 27:1-15), there were twelve divisions of generals, who commanded monthly, and whose duty was to keep guard on the royal person, each having a body of troops consisting of twenty-four thousand men, which, together, formed an army of two hundred eighty-eight thousand; and as a separate detachment of twelve thousand was attendant on the twelve princes of the twelve tribes mentioned in the same chapter, so both are equal to three hundred thousand. These were not reckoned in this book, because they were in the actual service of the king as a regular militia. But Ch1 21:5 joins them to the rest, saying, "all those of Israel were one million, one hundred thousand"; whereas the author of Samuel, who reckons only the eight hundred thousand, does not say, "all those of Israel," but barely "and Israel were," &c. It must also be observed that, exclusive of the troops before mentioned, there was an army of observation on the frontiers of the Philistines' country, composed of thirty thousand men, as appears from Sa2 6:1; which, it seems, were included in the number of five hundred thousand of the people of Judah by the author of Samuel. But the author of Chronicles, who mentions only four hundred seventy thousand, gives the number of that tribe exclusive of those thirty thousand men, because they were not all of the tribe of Judah, and therefore he does not say, "all those of Judah," as he had said, "all those of Israel," but only, "and those of Judah." Thus both accounts may be reconciled [DAVIDSON].
2 Kings (2 Samuel) 24:10
sa2 24:10HE, HAVING THREE PLAGUES PROPOUNDED BY GAD, REPENTS, AND CHOOSES THREE DAYS' PESTILENCE. (Sa2 24:10-14)
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.
2 Kings (2 Samuel) 24:13
sa2 24:13Shall seven years of famine come unto thee--that is, in addition to the three that had been already, with the current year included (see on Ch1 21:11).
2 Kings (2 Samuel) 24:14
sa2 24:14David said, . . . Let us fall now into the hand of the Lord--His overwhelming sense of his sin led him to acquiesce in the punishment denounced, notwithstanding its apparent excess of severity. He proceeded on a good principle in choosing the pestilence. In pestilence he was equally exposed, as it was just and right he should be, to danger as his people, whereas, in war and famine, he possessed means of protection superior to them. Besides, he thereby showed his trust, founded on long experience, in the divine goodness.
2 Kings (2 Samuel) 24:15
sa2 24:15HIS INTERCESSION TO GOD; THE PLAGUE CEASES. (Sa2 24:15-25)
from the morning--rather that morning when Gad came [Sa2 24:18], till the end of the three days.
there died of the people . . . seventy thousand men--Thus was the pride of the vainglorious monarch, confiding in the number of his population, deeply humbled.
2 Kings (2 Samuel) 24:16
sa2 24:16the Lord repented him of the evil--God is often described in Scripture as repenting when He ceased to pursue a course He had begun.
2 Kings (2 Samuel) 24:17
sa2 24:17David . . . said--or, "had said,"
I have sinned . . . but these sheep, what have they done?--The guilt of numbering the people lay exclusively with David. But in the body politic as well as natural, when the head suffers, all the members suffer along with it; and, besides, although David's sin was the immediate cause, the great increase of national offenses at this time had (Sa2 24:1) kindled the anger of the Lord.
2 Kings (2 Samuel) 24:18
sa2 24:18Araunah--or Ornan (Ch1 21:18), the Jebusite, one of the ancient inhabitants, who, having become a convert to the true religion, retained his house and possessions. He resided on Mount Moriah, the spot on which the temple was afterwards built (Ch2 3:1); but that mount was not then enclosed in the town.
2 Kings (2 Samuel) 24:21
sa2 24:21to build an altar unto the Lord, that the plague may be stayed--It is evident that the plague was not stayed till after the altar was built, and the sacrifice offered, so that what is related (Sa2 24:16) was by anticipation. Previous to the offering of this sacrifice, he had seen the destroying angel as well as offered the intercessory prayer (Sa2 24:17). This was a sacrifice of expiation; and the reason why he was allowed to offer it on Mount Moriah was partly in gracious consideration to his fear of repairing to Gibeon (Ch1 21:29-30), and partly in anticipation of the removal of the tabernacle and the erection of the temple there (Ch2 3:1).
2 Kings (2 Samuel) 24:23
sa2 24:23All these things did Araunah, as a king, give--Indicating, as the sense is, that this man had been anciently a heathen king or chief, but was now a proselyte who still retained great property and influence in Jerusalem, and whose piety was evinced by the liberality of his offers. The words, "as a king," are taken by some to signify simply, "he gave with royal munificence."
2 Kings (2 Samuel) 24:24
sa2 24:24Nay; . . . I will . . . buy it of thee at a price--The sum mentioned here, namely, fifty shekels of silver, equal Â£6 sterling, was paid for the floor, oxen and wood instruments only, whereas the large sum (Ch1 21:25) was paid afterwards for the whole hill, on which David made preparations for building the temple.
2 Kings (2 Samuel) 24:25
sa2 24:25David offered burnt offerings and peace offerings--There seem to have been two sacrifices; the first expiatory, the second a thanksgiving for the cessation of the pestilence (see on Ch1 21:26).