2 Samuel 21:3 - Ellicott's Commentary On The Whole Bible

Make the atonement. — This is the same technical word as is used throughout the Law in connection with the propitiatory sacrifices. It means literally, to cover up, and is here used in that literal sense. David asks what he can do to so cover up the sin of Saul as to remove it from the sight of those against whom it had been committed — the Gibeonites as the earthly sufferers from it, and God Himself as the one against whom he had chiefly offended. Then might God’s blessing again return to His people.