In Exodus 17:10, they signify divine truth in successive order, that is, divine truth immediately from the Lord, mediately from Him, and divine truth proceeding mediately from this. (Arcana Coelestia 8602)

8602. 'By fighting against Amalek' means against falsities arising from interior evil. This is clear from the representation of 'Amalek' as falsity arising from interior evil, dealt with above in 8593.