Second Samuel 21–24 is the final major section of 1–2 Samuel, and it explains why David, even after his failures, was the model king. These events are not necessarily placed in chronological order; they may have occurred earlier in David’s life than we would expect from their placement here. But they are placed here to reinforce certain themes, for the Bible often describes things out of chronological order in order to make theological points.
Today’s passage first shows us David’s commitment to righteousness. After a famine of three years, David sought the Lord (21:1), likely because prolonged famine was a covenant curse for persistent disobedience (Lev. 26:26). David wanted to know the sin causing the lack of food. God told him there was bloodguilt on the house of Saul because he put the Gibeonites to death (2 Sam. 21:1), an episode otherwise not mentioned in the Old Testament. You will remember that in the day of Joshua, the Israelites made a covenant never to destroy the Gibeonites (Josh. 9). Saul violated this covenant when he slaughtered the Gibeonites, and since his being the king made him the representative of Israel, the nation was suffering as a consequence of his sin.
According to Numbers 35:33, only blood atonement could cleanse the land of Saul’s sin and reverse the famine. Saul was dead, so his blood could not provide atonement. So, the Gibeonites asked for the death of Saul’s grandsons (2 Sam. 21:2–9). Ordinarily, children were not put to death for the sins of their fathers (Deut. 24:16), but this was no ordinary case. Saul represented Israel, and he had violated a national covenant with Gibeon made through Joshua and the nation’s leaders. The nation, thus, was collectively responsible for the sin. Instead of the nation’s dying, legitimate representatives of Saul and the nation—Saul’s grandsons—died. That David granted the Gibeonites’ request shows his commitment to covenant fidelity and to righteousness. Moreover, this helps us understand the atonement of Jesus. David and his descendants sinned, and Israel suffered as a result. Jesus, one of David’s descendants, atoned for the sins of David’s line and thereby turned away the curse on those whom David represented—all who trust in the God of Israel (Gal. 3:10–14).
Today’s passage also describes a successful war against the Philistines during David’s reign (2 Sam. 21:15–22). This demonstrates that David was faithful to God’s call on the monarchy to rescue Israel from the Philistines (1 Sam. 9:16).