Serpents represent what we know from our bodily senses, and the reasoning based on our senses. Since the people of the Most Ancient Church had become more external, they were susceptible to the lure of trusting their senses more than they trusted the leading of the Lord. That was particularly true for the sense of self the people had been given, which is represented by the woman. Eating of the trees in the garden represented taking in desires for good and true ideas from the knowledge granted them by the Lord.

So here, for the first time, we see people, from their own senses, actually questioning the Lord. From their senses they wished to explore the knowledge represented by fruit of the garden, but wondered why they were denied the tree of knowledge.

(Odkazy: Arcana Coelestia 194, 195, 196, 197)

1020. That these things are meant becomes clear from the fact that everything put together as history from Genesis 1 down to Eber in Chapter 11 means something different from what appears in the letter, and from the consideration that the historical narratives there are purely made-up history customary among the most ancient people. When attesting the truth of some matter they would say that 'Jehovah said it'. Here however 'God' is used because the subject is the spiritual Church. And they did the same when anything true was being, or had been, put into effect.