Arcana Coelestia #486
486. Verse 4 And the days of Man after he beget Seth were eight hundred years; and he beget sons and daughters.
'Days' means periods of time and states in general. 'Years' means periods of time and states in particular. 'Sons and daughters' means the truths and goods that they perceived.
Face of the deep
The face of the deep (Genesis 1:2) signifies the lust of the unregenerate man, and the falsities that originate from it.
(Referenties: Arcana Coelestia 018, Genesis 1)