1 Samuel 17:25
And the men of Israel said, Have ye seen this man that is come up? surely to defy Israel is he come up: and it shall be, that the man who killeth him, the king will enrich him with great riches, and will give him his daughter, and make his father’s house free in Israel.
Cross-reference
In 1 Samuel 17:27, the people repeat the exact reward terms to David — confirming the offer.
In 1 Samuel 18:17-27, Saul attempts to fulfill his promise of giving his daughter but sets a deadly trap — requiring Philistine foreskins as a dowry.
In 1 Samuel 22:14, Ahimelech calls David the king's son-in-law — showing the reward of Saul's daughter was fulfilled.
In Joshua 15:16, Caleb similarly offers his daughter as a reward for capturing Kiriath-sepher — mirroring Saul's offer of his daughter to Goliath's killer.
In Judges 1:12, Caleb similarly offers his daughter as reward for conquering Kirjath-sepher — a parallel to Saul's reward for killing Goliath.
In Judges 10:18, the Gileadites offer leadership to whoever fights Ammon — a different reward but same pattern of incentive for military victory.
In 2 Samuel 21:21, another giant defies Israel and is slain — echoing Goliath's defiance but without the reward offer.
In 1 Chronicles 11:6, David offers chief command to whoever first smites Jebusites — a reward for military feat like Saul's offer.