7644. 'And they will cover the surface of the land' means the lowest levels of the natural mind. This is clear from the meaning of 'the surface' as the external and so lowest levels; and from the meaning of 'the land', here 'the land of Egypt', as the natural mind, dealt with in 5276, 5278, 5280, 5188, 5301.

6614. I have been shown by actual experience how angelic ideas flow into the ideas of the spirits who are beneath them, therefore into ideas that are grosser. An abundance of ideas from the angelic heaven presented themselves visually as a shining white cloud that could be distinguished into separate little tufts; and each little tuft, which consisted of countless strands, presented a spirit with one simple idea. After that I was shown that such an idea contained thousands and thousands of strands, which were also represented by means of a cloud composed of the spirits' speech. After this I spoke to the spirits on these matters, saying that the objects of sight can be used by way of illustration. When an object which looks like a simple whole is examined with an optical device thousands of unseen details present themselves to view, as when tiny grubs which look like one dark blob are examined with a microscope; not only the multiplicity of them is seen but also the shape of each one. If even greater magnification is used to examine them, their organs, members, viscera, and vessels and fibres too can be seen. So also with the ideas constituting thought. Each one has thousands and thousands of strands to it; yet a number of ideas together from which a thought is formed are seen merely as a simple whole. Even so, the ideas that constitute one thought can contain more than the ideas constituting another. How much it contains is determined by its spread into communities round about.