9215. 'It is his clothing for his skin' means that they also clothe relatively external things. This is clear from the meaning of 'clothing' as the sensory level in general or things on that level, as above; and from the meaning of 'skin' as that which is relatively external, which also clothes more internal things but still exists within those on the sensory level. What 'the skin' means, and who exactly correspond to the skin in the next life, see 3540, 5552-5559, 8977, 8980. The natural degree of the human mind has a rather internal level, a relatively external or middle level, and an outermost level. The more internal level of the natural is in contact with heaven; the middle or relatively external level is in contact on one side with the more internal, and through this with heaven, and on the other side with the outermost, and through this with the world, see 4009, 4570, 5118, 5126, 5497, 5649, 5707. The outermost level of the natural is that of the senses, which is meant here by 'clothing'. This level receives impressions of objects in the world and thereby serves more internal things. It is called 'his only covering' because it is the last and lowest and so is general to all, the relatively external or middle level of the natural being the one meant by 'skin'. From this it is evident that 'his clothing for his skin' means that the sensory level also clothes relatively external things. The fact that the sensory level is the last and lowest of a person's life, and so is a general covering, see 4009, 5077, 5125, 5128, 5767, 5774, 6201, 6313, 7442, 7693.

5774. 'And each one loaded his ass, and they returned to the city' means that truths were brought back up from sensory impressions to known facts. This is clear from the meaning of an ass' as factual knowledge, dealt with in 5492, and of 'loading' it as bringing back up from sensory impressions since 'causing one's pouch to come down to the earth' means bringing the contents of the natural down to the level of sensory impressions, 5767 (raising 'the pouch' up from these is what 'loading' implies here); and from the meaning of 'the city' as truth present in doctrine, dealt with in 402, 2449, 2947, 3216.

[2] A brief explanation must be given of what bringing truths back up from sensory impressions to known facts is. Sensory impressions are one thing, known facts another, and truths yet another; they are consecutive to one another, for sensory impressions give rise to factual knowledge, and factual knowledge leads on to truths. Images that come in through the senses are stored in a person's memory; then he uses those images either to deduce a fact or to gain a perception of some fact he is learning about. After that he uses these facts either to deduce certain truths or to gain a perception of some truth he is learning about. This is the way everyone develops onwards from childhood. While he is a child a person's thought and grasp of things relies on sensory impressions; as he grows older his thought and grasp of things relies on factual knowledge, and after that on truths. This is the path leading to the power of judgement a person enters into as he matures.

[3] From this one may see that sensory impressions, known facts, and truths are distinct and separate. Indeed the three remain so distinct that sometimes a person's attention is fixed on sensory impressions, as happens when he gives thought only to what impinges on his senses; sometimes his attention is fixed on facts, as happens when he rises above sensory impressions and thinks more deeply; and at other times his attention is fixed on truths which have been inferred from facts, as happens when he thinks more deeply still. Anyone who stops to reflect can know these things from what is present within himself. In addition a person can bring truths down into known facts and see those truths within them, even as he can bring facts down into sensory impressions and consider them within these. And he can do the opposite. From all this one may see what is meant by bringing the contents of the natural down to the level of sensory impressions, and bringing truths back up from sensory impressions to known facts.