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.
Deuteronomy 24:17
17
You shall not wrest the justice [due] to the foreigner, [or] to the fatherless, nor take the widow's clothing to pledge;