This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

After the dancing girls sang, "Saul has killed his thousands, and David his tens of thousands."

1 Samuel 18:8-9 View context

And Saul was very wroth, and the saying displeased him; and he said, They have ascribed unto David ten thousands, and to me they have ascribed [but] thousands: and [what] can he have more but the kingdom?

And Saul eyed David from that day and forward.

After David bought Saul's daughter with 200 Philistine foreskins.

1 Samuel 18:27-29 View context

Wherefore David arose and went, he and his men, and slew of the Philistines two hundred men; and David brought their foreskins, and they gave them in full tale to the king, that he might be the king's son in law. And Saul gave him Michal his daughter to wife.

And Saul saw and knew that the LORD [was] with David, and [that] Michal Saul's daughter loved him.

And Saul was yet the more afraid of David; and Saul became David's enemy continually.