'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)

1834. That 'birds of prey came down on the carcasses' means evils and derivative falsities that wished to destroy is clear from the meaning of 'bird of prey' as falsity. In the Word a bird of prey means truth, as shown above, and also in the contrary sense falsity - that is, both meanings occur there, just as almost every other such expression in the Word has two meanings. That a bird of prey may also mean falsity has been shown already in 778, 866, 988. Anyone may see that certain arcana are meant by this reference to birds of prey coming down, otherwise this detail would not have been worthy of mention. Which particular arcanum is meant has also been stated already and is evident from the train of thought in the internal sense, namely that it is something regarding the state of the Church.

[2] When a Church is raised up by the Lord it is faultless to begin with. At that time one person loves another as his brother, as is well known from the Primitive Church after the Lord's Coming. In those days all members of the Church lived with one another as brothers; they also called one another brothers, and loved one another mutually. In the course of time however charity faded and passed away, and as it passed away evils took its place, and along with the evils falsities too wormed their way in. From this schisms and heresies resulted, which would never have existed if charity had continued to reign and live. In those days they would not even call schism schism, or heresy heresy, but a matter of doctrine adhered to in accordance with the particular belief of that schism or heresy. That matter of doctrine they would leave to each individual's conscience, provided it did not deny anything fundamental, that is, the Lord, eternal life, or the Word, and provided it was not contrary to Divine order, that is, to the Ten Commandments.

[3] The evils and derivative falsities which in the Church take the place of charity as it passes away are what is here meant by the birds of prey that Abram drove away, that is, that the Lord, whom Abram represents here, put to flight. Abram drove away nothing else than birds of prey, and nothing whatever of evil and falsity. Nor in heaven do they know of Abraham except as any other human being who of himself has no power to accomplish anything - for the Lord alone has such power, as is also stated in Isaiah,

You are our Father, for Abraham does not know us and Israel does not acknowledge us. You, O Jehovah, are our Father, our Redeemer; from of old is Your name. Isaiah 63:16.