(Exodus 17:16) "And he said: For (the) hand by the throne of Kah: The L–rd is at war with Amalek, etc.": R. Yehoshua says: When the Holy One Blessed be He sits on the throne of His kingdom, at that time "The L–rd is at war with Amalek."
The Rabbis Noticed This and Drew a Stunning Conclusion God's Name
Mekhilta Tractate Amalek 2:47