Arcana Coelestia#1797
1797. Verse 3 And Abram said, See, to me You have not given seed, and behold, a son of my house is my heir.
'Abram said, See, to me You have not given seed' means that there was no internal dimension of the Church, which is love and faith. 'Behold, a son of my house is my heir' means that in the Lord's kingdom there would be only that which is external.
Arcana Coelestia#256
256. Not only faith but also the Lord Himself is called 'the seed of the woman', because for one thing He alone imparts faith and so is faith itself, and for another He chose to be born, and in particular to be born within a Church which, on account of self-love and love of the world, had sunk completely into a hellish and devilish proprium. He did so in order that from His own Divine Power He might within His own Human Essence unite the Divine Celestial Proprium to the human proprium, so that they became one within Himself. Had He not united them the world would have perished completely. Since the Lord is accordingly 'the Seed of the woman', the seed is called 'He' and not 'it'.