A fruitful one signifies spiritual good from charity.

(References: Apocalypse Explained 357)

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.