In Amos 4:1, this signifies falsities of the natural man. (Arcana Coelestia 5198[3])

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.