Verse 30. "Because of the sword of the angel" - This is given as a reason why David built an altar in the threshing-floor of Ornan: he was afraid to go to Gibeon, because of the sword of the destroying angel, or he was afraid of delaying the offerings so long as his going thither would require, lest the destroying angel should in the mean while exterminate the people; therefore he hastily built an altar in that place, and on it made the requisite offerings, and by the fire from heaven God showed that he had accepted his act and his devotion. Such interventions as these must necessarily maintain in the minds of the people a full persuasion of the truth and Divine origin of their religion.
For a more circumstantial account of these transactions, see the notes on 2 Sam. xxiv. 1, Ac., in which several difficulties of the text are removed.