AGAG (ā'găg, Heb. ’ăghāgh, perhaps meaning violent). An important king of Amalek (Num.24.7). Balaam prophesied that a king of Jacob (Israel) would surpass him. In Num.24.3-Num.24.9 Balaam began to predict the coming prosperity of Israel. Israel’s oldest enemy following the Exodus was Amalek (Exod.17.8-Exod.17.15), and Balaam foresaw Israel’s future glory in terms of the defeat of Amalek under a king whom he identified as Agag. This prediction was fulfilled when Saul and Agag met in battle (1Sam.15.1-1Sam.15.33). Saul defeated Agag, but he only partly obeyed the command to wreak the Lord’s vengeance on the Amalekites. See also Saul.
AGAG ā’ găg (אֲגַג, perhaps high or warlike). A name or perhaps a title like Pharaoh belonging to an Amalekite king; one mentioned by Balaam in Numbers 24:7 and another by Saul in 1 Samuel 15:8, 9, 20, 32, 33. It appears that Haman was surnamed Agag also (Esth 3:1, et passim). The etymological meaning of the word is usually taken from Akkad. agāgum, “to get angry, furious.” M. Astour has recently pointed to the Gr. name Ogygos as being a Sem. name derived from ’āgag, “to flame” (“Greek and Semitic Names,” JNES, XXIII , p. 200.) Nothing is certain in these meanings. The name appears in Phoenician and Punic texts.
International Standard Bible Encyclopedia (1915)
A name, or title, applied to the king of the Amalekites, like Abimelech in Philistia and Pharaoh in Egypt. It is used of two of these kings:
(1) A king of Amalek, mentioned by Balaam (Nu 24:7) in his blessing of Israel;
(2) A later king, in the days of King Saul (1Sa 15). Saul was sent with his army to destroy the Amalekites, who had so violently opposed Israel in the Wilderness. He disregarded the Divine command, sparing the best of the spoil, and saving Agag the king alive (1Sa 15:8,9). After rebuking Saul, Samuel had Agag put to death for all the atrocities committed by himself and his nation (1Sa 15:32,33).