In Genesis 8:17, this signifies the internal man operating upon the external with increase of truth. (Arcana Coelestia 913)

In Deuteronomy 32:14, this signifies the goods of innocence. (Apocalypse Explained 314[7])

Breed also signifies matters relating to the intelligence and wisdom of the people of the Ancient Church. (Apocalypse Explained 374[10])

913. 'Let them spread out into the earth' means the action of the internal man into the external, while 'be fruitful' means increases in good, 'and multiply' increases in truth, and 'over the earth' means with the external man. This is clear from the train of thought and also from what has been stated and shown already about the meaning in the Word of 'being fruitful' as having reference to goods, and of 'multiplying' to truths. That 'the earth' means the external man has in like manner been shown already, so there is no need to pause and confirm these points. Here the subject is the action of the internal man into the external after a person has been regenerated. That is to say, when good starts 'to be fruitful' and truth 'to multiply', the external man is rendered correspondent or obedient. Until then this is not possible because the desires of the body are incompatible with goods, and the illusions of the senses with truths. The former annihilate the love of good, the latter the love of truth. The fruitfulness of good and the multiplication of truth take place in the external man - the fruitfulness of good in his affections, the multiplication of truth in his memory. The external man is here called 'the earth' into which mankind spreads out and over which they are fruitful and multiply.