38. Verse 18 And to have dominion over the day and the night, and to make a distinction between the light and the darkness; and God saw that it was good.

'The day' is used to mean good, and 'the night' evil. Consequently goods are called 'the works of the day', whereas evils are called 'the works of the night'. 'The light' is used to mean truth, and 'the darkness' falsity, just as the Lord says,

Men preferred darkness rather than light; he who does the truth comes to the light. John 3:19-21.

Verse 19 And there was evening, and there was morning, a fourth day.

In Exodus 15:8, this signifies falsities gathered together. Waters normally signify truths, but in this case, where they were blocking the escape of the Children of Israel from slavery and signify the opposite: falsities.

(References: Arcana Coelestia 8286)