During David’s reign there was a famine for three successive years, so David inquired of the Lord. The Lord answered, “It is because of the blood shed by Saul and his family when he killed the Gibeonites.”
The Gibeonites were not Israelites but rather a remnant of the Amorites. The Israelites had taken an oath concerning them, but Saul had tried to kill them in his zeal for the Israelites and Judah. So David summoned the Gibeonites and spoke to them. He asked the Gibeonites, “What should I do for you? How can I wipe out this guilt so that you will bring a blessing on the Lord’s inheritance?”
The Gibeonites said to him, “We are not asking for money from Saul or his family, and we cannot put anyone to death in Israel.”
“Whatever you say, I will do for you,” he said.
They replied to the king, “As for the man who annihilated us and plotted to exterminate us so we would not exist within the whole territory of Israel, let seven of his male descendants be handed over to us so we may hang them in the presence of the Lord at Gibeah of Saul, the Lord’s chosen.”
The king answered, “I will hand them over.” (2 Samuel 21:1-6)
Going back on a promise will cost you, with unpredictable consequences. During the time of Joshua, when the Israelites were conquering the Canaanites and wiping them out, one group of them from a place called Gibea pretended to come from a long ways off. God had prohibited Israel from making treaties of peace with any Canaanites, but it was fine if they made them with other people. So the Israelites made a treaty with them. Of course, the Israelites soon learned of the subterfuge, but because of the treaty, these Canaanites came under Israel’s protection. The Gibeonites, like Rahab in Jericho, had turned to God.
In his zeal to wipe out the remaining Canaanites, Saul had also attacked the people of Gibea. Thanks to a famine, David learned what Saul had done and agreed to go along with the Gibeonite’s request for vengeance. How could it be right that Saul’s sons would die for their father’s crime?
The Gibeonites had repented and come under the protection of the Israelites. Saul had violated that: he had attacked the innocent. Like Jonathan, his sons had served as soldiers in Saul’s army. They had participated in their father’s crime, and so they suffered the just consequences.