Arcana Coelestia #61
61. Everything that has to do with cognitions of faith is called spiritual, and everything that has to do with love to the Lord and towards the neighbour is called celestial. The former belong to man's understanding, the latter to his will.
Ephesians 3:9
9
and to make all men see what is the administration of the mystery which for ages has been hidden in God, who created all things through Jesus Christ;