'Leaves' symbolize rational truths because a tree symbolizes a person, and every part of the tree symbolizes accordant elements in the person.

(Odkazy: Apocalypse Revealed 936; Arcana Coelestia 884, Genesis 8:11; Revelation 22:2)

926. It is clear from what follows that 'Jehovah said in His heart' means that it would never happen again. When the verb 'says' is used of Jehovah, nothing else is meant than 'is so' or 'is not so', or 'happens' or 'does not happen'; for no other verb can be used of Jehovah than Is. The things which are said of Jehovah throughout the Word are there for the benefit of people who cannot grasp anything apart from that which comes within man's actual experience. That is why the sense of the letter takes the form it does. The simple in heart are able to be taught from appearances as they belong to man's actual experience, for their knowledge of things goes scarcely any further than that based on sensory experience; therefore it is their mental grasp of things that determines the way anything is said in the Word, as is the case here with the statement 'Jehovah said in His heart'.