909. 'Birds' means things of his understanding and 'beasts' those of his will, [both of] which belong to the internal man; and 'every creeping thing that creeps over the earth' means corresponding things of a like nature residing with his external man. This becomes clear from the meaning of 'a bird', dealt with already in 40, 776, and of 'a beast' in 45, 46, 142, 143, 246. That 'creeping thing that creeps over the earth' means corresponding things residing with the external man is clear from this. Indeed 'creeping thing that creeps' here stands in relation both to 'birds', or things of the understanding, and to 'beasts', or those of the will. The most ancient people used to call the sensory powers and the appetites of the body 'creeping things that creep' because they are indeed just like reptiles that creep along the ground. They also likened the human body to the earth or to the ground. Indeed they actually called it the earth or the ground, as in the present verse where nothing other than the external man is meant by 'the earth'.

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.