Deuteronomy 25:17

But whilst the Israelites were to make love the guiding principle of their conduct in their dealings with a neighbour, and even with strangers and foes, this love was not to degenerate into weakness or indifference towards open ungodliness. To impress this truth upon the people, Moses concludes the discourse on the law by reminding them of the crafty enmity manifested towards them by Amalek on their march out of Egypt, and with the command to root out the Amalekites (cf. Exo 17:9-16). This heathen nation had come against Israel on its journey, viz., at Rephidim in Horeb, and had attacked its rear: "All the enfeebled behind thee, whilst thou wast faint and weary, without fearing God." זנּב, lit., to tail, hence to attack or destroy the rear of an army or of a travelling people (cf. Jos 10:19). For this reason, when the Lord should have given Israel rest in the land of its inheritance, it was to root out the remembrance of Amalek under heaven. (On the execution of this command, see 1 Sam 15.) "Thou shalt not forget it:" an emphatic enforcement of the "remember" in Deu 25:17.

Here is, I. A law to moderate the scourging of malefactors (Deu 25:1-3). II. A law in favour of the ox the treads out the corn (Deu 25:4). III. For the disgracing of him that refused to marry his brother's widow (Deu 25:5-10). IV. For the punishment of an immodest woman (Deu 25:11, Deu 25:12). V. For just weights and measures (Deu 25:13-16). VI. For the destroying of Amalek (Deu 25:17, etc.).

25:17 The Amalekites were tribal peoples who attacked Israel’s rear flanks during the Sinai wilderness wandering (Exod 17:8-16). They were apparently related to the Edomites (Gen 36:12).