An act of justice, stern and terrible, was yet to be performed. Samuel must publicly vindicate the honor of God and rebuke the course of Saul. He commanded that the king of the Amalekites be brought before him. Above all who had fallen by the sword of Israel, Agag was the most guilty and merciless; one who had hated and sought to destroy the people of God, and whose influence had been strongest to promote idolatry. He came at the prophet's command, flattering himself that the danger of death was past. Samuel declared: "As thy sword hath made women childless, so shall thy mother be childless among women. And Samuel hewed Agag in pieces before the Lord." This done, Samuel returned to his home at Ramah, Saul to his at Gibeah. Only once thereafter did the prophet and the king ever meet each other.

Retfærdigheden var endnu ikke sket fyldest. Der forestod en grusom og frygtelig handling. Samuel skulle i hele folkets påsyn hævde Guds ære og fordømme Sauls handlemåde. Han befalede, at amalekitternes konge skulle føres hen til ham. Agag var den mindst skyldfrie og den mest ubarmhjertige af alle dem, som Israel havde overvundet med sværdet. Han hadede Guds folk og havde gjort alt for at udrydde dem. Desuden havde han øvet en vældig indflydelse for at fremme afgudsdyrkelsen. Han kom på profetens befaling og smigrede sig med, at der nu ikke længer var fare for hans liv. Samuel sagde: "Som dit sværd har gjort kvinder barnløse, skal din moder blive barnløs frem for andre kvinder!" Derpå sønderhuggede Samuel Agag for Herrens åsyn i Gilgal." Da det var gjort, begav Samuel sig til sit hjem i Rama, mens Saul drog op til sit hjem i Gibea. Dette var det næstsidste møde mellem profeten og kongen.