2 Samuel 21:9
And he delivered them into the hands of the Gibeonites, and they hanged them in the hill before the LORD: and they fell all seven together, and were put to death in the days of harvest, in the first days, in the beginning of barley harvest.
David handed seven of Saul's descendants over to the Gibeonites, who hanged them together on a hill before the Lord in the first days of the barley harvest. Those first days of harvest were at the beginning of May. The bodies remained there through the night, contrary to the law requiring the bodies of the hanged to be taken down before sunset, for an unknown reason, and the verse sets the scene for Rizpah's vigil beside the bodies.
God holds His people collectively responsible for the transgressions of a few when the rest allow the sin to continue. In ancient Israel an offense by one person could be reckoned against the whole family as a united social body, so the execution of Saul's seven descendants shows the family being held responsible for the wrong. God does not tolerate oppression, even when it is directed against people outside the household of faith. The deaths and public hanging came as a judgment upon David after his great transgression, belonging to the later history in which Nathan's denunciation was fulfilled through judgments on David.