Why then have you despised the command of the LORD by doing evil in His sight? You put Uriah the Hittite to the sword and took his wife as your own. You have slain him with the sword of the Ammonites.
It seems to have been a great while after David had been guilty of adultery with Bath-sheba before he was brought to repentance for it. For, when Nathan was sent to him, the child was born (Sa2 12:14), so that it was about nine months that David lay under the guilt of that sin, and, for aught that appears, unrepented of.
Commenting on 2 Samuel 12:1-14
Now therefore the sword shall never depart from thine house,.... During his life, and as appeared in the slaughter of his sons Ammon and Absalom before his death, and of Adonijah quickly after, and in his posterity through their wars with the children of Israel, and other nations: because thou hast despised me; his commandments, and that in effect was despising him the lawgiver: and...
Wherefore hast thou despised the commandment of the LORD, to do evil in his sight? thou hast killed Uriah the Hittite with the sword, and hast taken his wife [to be] thy wife, and hast slain him with the sword of the children of Ammon. (e) You have most cruelly given him into the hands of God's enemies.