4930. 'And he called his name Zerah' means the essential nature of it. This is clear from the meaning of 'calling the name' as the essential nature, as above in 4927. The essential nature meant by 'Zerah' is the nature of the reality which has been the subject in the internal sense up to this point, this reality being that in actual fact good is the firstborn but that truth appears to be such. That nature contains countless details, countless details such as cannot be seen in the light of the world, only in the light of heaven, and so by the eyes of the angels. If man could see the essential nature of a single reality like those visible to the angels he would be dumbfounded and would confess he would never have believed it, adding that compared with the angels he knew scarcely anything. In the original language Zerah means 'the rise' and is used to refer to the sun and the first sign of its light. This explains why this son was named Zerah, for good behaves in a similar way in the case of one who is being regenerated. Good first rises and sheds light, and from this light things within the natural man are lightened, enabling them to be seen, acknowledged, and finally believed. If light did not flow from the good present within that person he would never be able to see truths so that he could acknowledge and believe them. Instead he would see them as no more than the kind of things that have to be called truths for the common people's sake, or else as falsities.