Contradiction with Genesis 6:6
Here, God expresses regret for making humans, which contradicts the notion of God's purposeful decision and foresight in choosing leaders such as in 1 Samuel 16:1.
Genesis 6:6: And it repented the LORD that he had made man on the earth, and it grieved him at his heart.
Contradiction with Numbers 23:19
This verse emphasizes that God does not change His mind, contradicting any implication in 1 Samuel 16:1 that God might regret His previous choice of Saul as king.
Numbers 23:19: God [is] not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do [it]? or hath he spoken, and shall he not make it good?
Contradiction with Malachi 3:6
It states that God does not change, which contradicts with God choosing a new king in 1 Samuel 16:1, suggesting a change in His plan.
Malachi 3:6: For I [am] the LORD, I change not; therefore ye sons of Jacob are not consumed.
Contradiction with James 1:17
This verse mentions that there is no variableness in God, contrasting with the change of circumstances regarding Saul and the appointment of a new king as seen in 1 Samuel 16:1.
James 1:17: Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning.