'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)

10691. 'That Moses did not know that the skin of his face gleamed while he talked to Him' means the inward level or aspect of the Word within the outward, shining forth without any perception of it by the outward. This is clear from the representation of 'Moses' as the outward form of the Word containing what is inward, dealt with in 10563, 10571, 10607, 10614; from the meaning of 'not knowing' as not perceiving; from the meaning of 'gleaming' as shining forth, for the gleaming of the skin of Moses' face is a shining forth from what is inward; from the meaning of 'the skin' as the outward level of truth and good, dealt with in 3540, 5554, 8980; from the meaning of 'face' as interior things, dealt with in the places referred to 9546, so that 'the gleaming of the skin of the face' means a shining forth of the interior things within what is external or outward, at this point within the outward form the Word takes, which is its literal sense, since Moses represents the outward form of the Word containing what is inward; and from the meaning of 'talking' as influx, for 'talking', when it has regard to Jehovah, means influx, see 2951, 5743, 5797, 7270, 8128, 8660. From all this it is evident that 'Moses did not know that the skin of his face gleamed while he talked to Him' means the inward level of the Word within the outward, shining forth without any perception of it by the outward. It should be recognized that by a shining forth of the interiors of the Word within what is outward the internal sense within the external should be understood. The internal sense shines forth unceasingly and gleams within the external, yet it is discerned only by those whose affection is for inward things. It is not discerned by those whose affection is for the outward that contains what is inward, that is, by those people who are called members of the external Church. Nevertheless that sense is present with them, without their awareness, and exerts an influence on them. Who exactly they are whose affection is for the inward level or aspect of the Word, the Church, and worship, and who exactly they are whose affection is for the outward level or aspect of them that has the inward within it, see above in 10683. But when people's interest lies in the outward level devoid of the inward, as was so with the Israelite nation, they cannot at all abide the inward level of them or the light from them within the outward. This explains why in the verses that follow it says that they were afraid to approach Moses and that when Moses talked to them he put a veil over his face. The reason why the internal sense shines forth is that Divine Truth as it exists in the heavens resides in that sense, and Divine Truth emanating from the Lord appears to angels as light and also constitutes the light of heaven. For this matter, see in the places referred to in 9548, 9684.