In the ancient and Jewish churches, 'songs' were prophesies about the Lord, especially His coming in the world, subjugation of evil spirits, and liberation of the faithful from their assaults. 'Heavenly songs' are voiced affections or affections expressed and modified by sounds. As thoughts are expressed by conversation, so affections are expressed by songs. From the balance and flow of the variations, angels perceive the object of the affection.

(Reference: Conjugial Love 55)

2048. That 'he who is born in the houses means celestial people, and 'he who is the purchase of silver' spiritual people, and so those who are inside the Church, is clear from the meaning of 'him born in the house' as those inside the house. In the Word 'a house' means that which is celestial because this is inmost. Consequently 'the house of God' means in the universal sense the Lord's kingdom, in a less universal sense the Church, and in a particular sense the individual himself in whom the Lord's kingdom or Church exists. When a person is called 'a house' it means the celestial side of faith with him, but when he is called 'a temple' it means the truth of faith with him. So 'he who is born in the house' here means celestial people. That 'the purchase of silver' or one bought with silver means spiritual people however is clear from the meaning of 'silver' as truth, and so the spiritual side of faith, dealt with in Volume One, in 1551.

[2] The expression celestial is used of those who are governed by love to the Lord, and because the Most Ancient Church which existed before the Flood was governed by that love it was a celestial Church. The expression spiritual is used of those who are governed by love towards the neighbour and so by the truth of faith. This was the character of the Ancient Church that existed after the Flood. The difference between celestial people and spiritual has been dealt with many times in Volume One. Anyone may see that there are heavenly arcana here, that is to say, in the requirement to circumcise those born in the house and those bought with silver, also sons who were foreigners, and in the fact that those persons are mentioned repeatedly, for example, in verses 13, 23, 27, that follow. These arcana are not apparent however except from the internal sense, that is to say, that those born in the house and those bought with silver mean celestial people and spiritual, and so those inside the Church - while 'the son who is a foreigner and not of your seed' means those outside the Church.