Arcana Coelestia#21
21. Verses 4-5 And God saw that the light was good; and God made a distinction between the light and the darkness. And God called the light Day, and the darkness He called Night.
The light is called good, because it comes from the Lord, who is good itself. 'The darkness' is those things which were there prior to the person's new conception and birth. They were seen as light, because evil was seen as good, and falsity as truth. But in reality they are darkness and things proper to that person which are lingering on. All things that are the Lord's, being things of light, are compared to the day, and all that are man's own, being those of thick darkness, are compared to the night, as is done many times in the Word.
Arcana Coelestia#6267
6267. 'And Joseph took them both, Ephraim in his right hand to Israel's left' means truth belonging to the understanding, to occupy the second place, 'and Manasseh in his left to Israel's right' means good belonging to the will, to occupy the first place. This is clear from the representation of 'Ephraim' as truth belonging to the understanding, and from the representation of 'Manasseh' as good belonging to the will, dealt with in 5354, 6222; and from the meaning of 'the right' as occupying the first place, and of 'the left' as occupying the second place, as is evident from what is the normal practice in life. The implications of all this will be discussed in what follows below.