670. That 'living creature' ¹ means things of the understanding, and 'all flesh' those of the will, becomes clear from what has been stated already, and also from what follows. In the Word 'living creature' means all animal life in general, as in Genesis 1:10, 21, 24; 2:19. Here however, because the phrase 'all flesh' is added immediately after, it means things which belong to the understanding, for the reason given already, that the regeneration of the member of this Church had to begin in the things of the understanding. This also is why in the next verse 'birds' are mentioned first, which mean things of the understanding or the rational, and 'beasts', which are those of the will, second. 'Flesh' in particular means bodily-mindedness which is a feature of the will.

Footnotes:

In general, trees represent the deepest and most significant intellectual concepts: the ones that come to us most directly from the Lord. This varies depending on us and our states: the people of the Most Ancient Church, who were in a state of loving the Lord, understood truth automatically and internally through what the Writings call "perception"; people in lower states (including most of us) have to work a little harder to learn it from the Word and by willing to follow the Lord. In other parts of the Bible, especially in the prophets and New Testament parables, the meaning of "tree" is broader, meaning not just a person's intellectual concepts but the whole person.

'Trees,' as in Joel 1:10-12, signify knowledges.