Arcana Coelestia #3926
3926. 'A second son to Jacob' means a second general truth. This is clear from the meaning of 'son' as truth, dealt with in 489, 491, 533, 1147, a general truth being meant at this point, as is clear from what has been stated and shown above concerning the twelve sons of Jacob and concerning the twelve tribes named after them; that is to say, the general aspects of the Church, and consequently the general aspects of faith and love, or of truth and good, are meant and represented by those sons. They also mean in the contrary sense every general aspect of that which is not faith or love, that is, every aspect of falsity and evil, as will be evident from what is said further on.
Arcana Coelestia #1147
1147. 'And sons were born to them' means matters of doctrine deriving from those three. This is clear from the meaning of 'sons' in the internal sense as truths of faith, and also as falsities. Consequently matters of doctrine, both true and false, are meant, for such are the doctrines of Churches. That 'sons' has such a meaning, see above in 264, 489, 491, 533.