In Isaiah 46:3, 4, a man who is regenerated by the Lord, is first of all conceived, and afterwards born, and at length educated and perfected, and since regeneration in this respect is like the natural generation of man, therefore, being born from the belly represents the state of man while he is regenerating.

(Referenties: Apocalypse Explained 710)

5348. 'And to Joseph were born two sons' means the good and truth born from this, that is to say, from the influx of the celestial of the spiritual into the natural. This is clear from the meaning of 'being born' as being reborn, and so the birth of truth derived from good or faith derived from charity, dealt with in 4070, 4668, 5160 (for the generations described in the Word are spiritual ones, see 1145, 1255, 1330, 3263, 3279, 3860, 3866); and from the meaning of 'sons', who in this case are Manasseh and Ephraim, as good and truth, dealt with immediately below. For 'Manasseh' means the area of will belonging to the new natural, while 'Ephraim' means the area of understanding belonging to it. Or what amounts to the same, 'Manasseh' means the good present in the new natural, since good exists as an attribute of the will, while 'Ephraim' means the truth present there, since truth exists as an attribute of the understanding. One reads in other places about the birth of two sons. Good is meant by one, truth by the other, as for instance with Esau and Jacob. 'Esau' means good, see 3302, 3322, 3494, 3504, 3576, 3599, while 'Jacob' means truth, 3305, 3509, 3525, 3546, 3576. The like is meant by Judah's two sons by Tamar, Perez and Zerah, 4927-4929; and the same applies here in the case of Manasseh and Ephraim. The birth of these is dealt with here because the subject in what went immediately before this was the influx of the celestial of the spiritual into the natural and the consequent rebirth of it, which is effected solely by means of good and truth.

4668. 'These are the generations of Jacob' means the things that follow. This is clear from the meaning of 'generations' as derivatives of the things which constitute the Church - truth derived from good, or faith from love - for no other generations are meant in the internal sense of the Word. These are also the subject in what follows, and this is why it is said that 'the generations of Jacob' means the things which follow. That things like these are meant by 'generations' is also evident from the fact that in what follows no subsequent generations are recorded. Instead Joseph, his dreams, his brothers' designs against him are described, and lastly the carrying away of him into Egypt. As regards 'generations' meaning derivatives of the kinds of things mentioned above, see 1145, 1255, 1330, 3263, 3279, 3860, 3868, 4070.