'Skins' or 'hides' signify external things, because the hide is the outermost organ of an animal where its interiors extend, the same as with a person's dermis or skin. 'Skin' corresponds to truth or to falsity in the extremes. See Arcana Coelestia 1835, 10036, and Apocalypse Explained 386. 'Skin,' as in Job 19:26, means the natural degree a person has with him after death.

In Exodus 22:27, this signifies things that are relatively external. (Arcana Coelestia 9215)

In Exodus 34:29, this signifies the internal of the Word shining from the external. (Arcana Coelestia 10691)

In Job 19:20, this signifies being not entirely in falsities. (Apocalypse Explained 556[11])

In Jeremiah 13:23, this signifies that evil cannot change its nature. (Apocalypse Explained 780[5])

In Genesis 3:21, this signifies that the Lord instructed them in spiritual and natural good. (Arcana Coelestia 292)

In Genesis 27:16, this signifies the external truths of domestic good. (Arcana Coelestia 3540)

5767. 'And caused to come down, each one his pouch to the earth' means that they brought the contents of the natural down to the level of sensory impressions This is clear from the meaning of 'causing to come down' - when these words are anticipating those that immediately follow them - as bringing to; from the meaning of 'pouch' as the exterior natural, dealt with in 5497; and from the meaning of 'the earth', when it says that they caused their pouches to come down to it, as the ultimate or lowest, thus the sensory level. For this level is the lowest or ultimate one since the senses are positioned at the doorway to the world outside. Bringing down to sensory impressions implies a thorough verification that a thing is so, for in this case even sensory evidence testifies to the inference that is being drawn.