26. Verse 8 And there was evening, and there was morning, a second day.

What 'evening', 'morning', and 'day' mean, has been shown already at verse 5.

116. The Sun in Heaven

Our world's sun is not visible in heaven, and neither is anything that is derived from it, since all that is natural. Nature, in fact, begins with that sun, and whatever is produced by it is called natural. The spiritual reality in which heaven exists, though, is above nature and completely distinct from anything natural. They communicate with each other only through correspondences.

The nature of the distinction can be gathered from what was said above about levels in 38, and the nature of the communication from the last two chapters about correspondences.