Why was King David spared of the death-for-death rule of Exodus 21?

We read in Ex 21: 12-14 (NRSVCE): > Whoever strikes a person mortally shall be put to death. If it was not premeditated, but came about by an act of God, then I will appoint for you a place to which the killer may flee. But if someone willfully attacks and kills another by treachery, you shall take the killer from my altar for execution. Now, 2 Samuel 11 narrates how King David got Uriah the Hittite killed in war in a deceitful manner so as to marry his would-be-widow Bathsheba. Of course, David repents at the intervention of prophet Nathan , and is punished by God with the death of his fist child born of Bathsheba ( 2 Sam 12). But the rule of death-for-death in Ex 21, which spared not even the priests, does not appear to have been implemented in the case of David. My question therefore is: **Why was King David spared of the death-for-death rule of Exodus 21?** Inputs from any denomination are welcome.