Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
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1 Samuel 15:20

Saul said to Samuel, “But I have obeyed Yahweh’s voice, and have gone the way which Yahweh sent me, and have brought Agag the king of Amalek, and have utterly destroyed the Amalekites.

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