Contradiction with 1 Samuel 16:21
In 1 Samuel 17:22, David is portrayed as leaving his things with the keeper, whereas in 1 Samuel 16:21, he already served Saul, indicating a lack of continuity in his role.
1 Samuel 16:21: And David came to Saul, and stood before him: and he loved him greatly; and he became his armourbearer.
Contradiction with 1 Samuel 17:55
In 1 Samuel 17:22, David is already interacting with the army, yet in 1 Samuel 17:55, Saul appears not to know David, suggesting a contradiction in their familiarity.
1 Samuel 17:55: And when Saul saw David go forth against the Philistine, he said unto Abner, the captain of the host, Abner, whose son [is] this youth? And Abner said, [As] thy soul liveth, O king, I cannot tell.
Contradiction with 1 Chronicles 22:8
Here, David is depicted as a man of war, whereas 1 Samuel 17:22 shows him entering the battle scene with simplicity, putting into question his initial battlefield experience.
1 Chronicles 22:8: But the word of the LORD came to me, saying, Thou hast shed blood abundantly, and hast made great wars: thou shalt not build an house unto my name, because thou hast shed much blood upon the earth in my sight.
Contradiction with 2 Samuel 21:19
This verse suggests a different person killed Goliath, creating a contradiction with the account leading up to 1 Samuel 17:22, where David is preparing for such an encounter.
2 Samuel 21:19: And there was again a battle in Gob with the Philistines, where Elhanan the son of Jaareoregim, a Bethlehemite, slew [the brother of] Goliath the Gittite, the staff of whose spear [was] like a weaver's beam. [Jaareoregim: or, Jair]