To be fruitful relates to goodnesses, and to be multiplied, truths.

(Notae: Arcana Coelestia 1014, 1018)

1014. Verse 7 And you, be fruitful and multiply; swarm over the earth and multiply in it.

'Be fruitful and multiply' here, as previously, means increases in good and truth in the interior man, 'being fruitful' having reference to goods, and 'multiplying' to truths. 'Swarm over the earth and multiply in it' means increases in good and truth in the external man, which man is 'the earth' - 'swarming' having reference to goods, 'multiplying' to truths.