Deuteronomy 25:17

Remember what Amalek did unto thee by the way, when ye were come forth out of Egypt;

Moses gave a solemn charge just before his death never to forget what Amalek did to Israel by the way when coming out of Egypt during the wilderness journey. The command to remember was joined to the command not to forget and, after Israel received rest in its inheritance in the promised land, to blot out the remembrance of Amalek from under heaven. Amalek met Israel by the way and smote the hindmost, all that were feeble and defenseless behind, when Israel was faint and weary. He feared not God, taking advantage of their circumstances to injure, harass, confuse, discourage and bring suffering upon weary stragglers fallen behind the body under God's leading. It was a cowardly and cruel attack in which the stragglers were slain.

The assault was wholly unprovoked, for Israel had not injured or threatened Amalek. Amalek knew God's character and sovereignty from the wonders done before the Egyptians, yet instead of fearing Him mocked them. He ridiculed the fears of surrounding nations, swore by his gods to destroy the Hebrews so none should escape, and boasted that Israel's God could not resist or rescue them. Amalek had long been high-handed sinners whose crimes cried for vengeance while mercy still called them to repentance, but by falling on the wearied ranks they sealed their nation's doom. Their hostility manifested hatred and defiance of God in an attack against God and His throne to destroy His people, which God marked.

Israel was to carry out God's judgment to fulfill His word, with destruction appointed through the people Amalek had despised so all nations could see the end of a proud and powerful people who defied Him. That work was not to enrich Israel or bring it glory or plunder, for Israel was to keep nothing belonging to Amalek because God had cursed Amalek and its possessions. Saul's preservation of what God had appointed for destruction defied that command. The verse reveals God's tender and jealous care over the weakest of His children even though Israel had often grieved the Lord by departing from His counsel, seen in Jesus Christ marking and seeing the wrong done them as they journeyed under God's leading. No cruelty or oppression toward them goes unmarked, His hand is a shield over all who love and fear Him so those who smite them strike that hand which wields the sword of justice, and it carries His pledge to bless those who walk in His way and do justice and judgment.

The verse warns those who profess to be God's children not to receive Amalek's curse by following Amalek's practices toward their own brethren and worn and wearied fellow laborers. If a heathen nation was denounced and punished for overcoming the faint and weary, those with light, opportunities and privileges who do not manifest the Spirit of Christ will face even greater displeasure. For God witnesses every act of injustice and oppression and will bring all their works into judgment. Amalek's exploitation of weakness applies as a lesson against watching for the weaknesses, failings and failures of God's afflicted people in order to expose and use them to harm them before their enemies. This too is a serious sin that serves Satan rather than God.