2 Samuel 12:9 - Joseph Benson’s Commentary on the Old and New Testaments

Thou hast killed Uriah David's contriving his death was as bad as if he had killed him with his own hand. With the sword of the children of Ammon This was an aggravation of his crime, that he caused him to be slain by the professed enemies of God, who doubtless triumphed in the slaughter of so great a man. Hast taken his wife, &c. To marry her whom he had defiled, and whose husband he had slain, was an affront upon the ordinance of marriage, making that not only to palliate, but in a manner to consecrate such villanies. In all this he despised the word of the Lord; (so it is in the Hebrew;) not only his commandment in general, but the particular word of promise, which God had before sent him by Nathan, that he would build him a house: which sacred promise if he had had a due value for, he would not have polluted his house with lust and blood.