1 Samuel 20:16

So Jonathan made a covenant with the house of David, saying, Let the Lord even require it at the hand of David’s enemies.

Cross-reference

1 Samuel 20:8 contains David's earlier appeal to the same covenant — directly connected to the covenant ratification in verse 16.

In 1 Sam 18:3, Jonathan first made a covenant with David out of love—this earlier covenant is the foundation for the one renewed in 20:16.

In 1 Sam 31:2, Jonathan is killed in battle—the covenant of friendship with David stands in tragic contrast to his death.

2 Samuel 4:8 has the assassins claim God avenged David on Saul's offspring — a direct echo of the covenant curse on David's enemies.