Deuteronomy Chapter 25, Verse 19

19: Therefore it shall be, when the LORD thy God hath given thee rest from all thine enemies round about, in the land which the LORD thy God giveth thee for an inheritance to possess it, that thou shalt blot out the remembrance of Amalek from under heaven; thou shalt not forget it.— edit KJV text
19: Therefore when the Lord thy God shall give thee rest, and shall have subdued all the nations round about in the land which he hath promised thee: thou shalt blot out his name from under heaven. See thou forget it not.— edit Douay text
19: And it shall come to pass whenever the Lord thy God shall have given thee rest from all thine enemies round about thee, in the land which the Lord thy God gives thee to inherit, thou shalt blot out the name of Amalec from under heaven, and shalt not forget [to do it].— edit LXX text