Contradiction with Numbers 3:10
It states that only Aaron and his descendants should minister as priests, while 2 Samuel 8:18 mentions David's sons being priests.
Numbers 3:10: And thou shalt appoint Aaron and his sons, and they shall wait on their priest's office: and the stranger that cometh nigh shall be put to death.
Contradiction with 1 Chronicles 18:17
States that David's sons were chiefs at the king's side, not priests.
1 Chronicles 18:17: And Benaiah the son of Jehoiada [was] over the Cherethites and the Pelethites; and the sons of David [were] chief about the king. [about...: Heb. at the hand of the king]
Paradox #1
The possible conflict or inconsistency with 2 Samuel 8:18 is that it mentions David’s sons were priests. According to other parts of the Bible, only Levites, specifically descendants of Aaron, were supposed to be priests. This could seem inconsistent with the religious laws outlined in earlier texts.
Paradox #2
2 Samuel 8:18 mentions that David’s sons were priests, which could be seen as a contradiction or inconsistency because, according to other parts of the Bible, only descendants from the tribe of Levi were supposed to be priests. David's family was from the tribe of Judah. This could create a conflict with the established religious rules of who can be a priest.