Deuteronomy 25:17-19

17“Remember what Amalek did to you along the road when you came from Egypt,

18how he met you along the road and attacked all the stragglers at your rear when you were tired and weary; and he did not fear God.

19Therefore when the Lord your God has given you rest from all your surrounding enemies, in the land which the Lord your God gives you as an inheritance to possess, you shall wipe out the memory of Amalek from under heaven; you must not forget.