Deuteronomy 25:17-19

17“1Remember what Amalek did to you along the way when you came out from Egypt,

18how he met you along the way and attacked among you all the stragglers at your rear when you were faint and weary; and he 2did not 3fear God.

19Therefore it shall come about when the Lord your God has given you 4rest from all your surrounding enemies, in the land which the Lord your God gives you as an inheritance to 5possess, you shall blot out the memory of Amalek from under heaven; you must not forget.