'A palace,' as in Psalm 144:12, represents the understanding in which truths have a beautiful form. They have a beautiful form when they are from affection for truth. 'A palace,' as in Amos 4:3, signifies the Word, and consequently, the truth of doctrine which is from good. 'A palace,' as in Isaiah 32:14, signifies the whole church regarding truths from good.

(Odkazy: Apocalypse Explained 721)

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.