Contradiction with James 2:13
This verse emphasizes mercy, stating that "mercy rejoiceth against judgment," which may seem contradictory to the concept of judgment prevalent in David's motivations and actions.
James 2:13: For he shall have judgment without mercy, that hath shewed no mercy; and mercy rejoiceth against judgment. [rejoiceth: or, glorieth]
Contradiction with Proverbs 11:17
Suggests that a merciful person does good to their own soul, which could be seen as at odds with acts motivated by reasons other than pure kindness, such as political motives or obligations.
Proverbs 11:17: The merciful man doeth good to his own soul: but [he that is] cruel troubleth his own flesh.