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.

5194. 'And it happened at the end of two years of days' means after the state when the joining together took place, that is to say, when the powers of the senses belonging to the exterior natural and those belonging to the interior natural were joined together, both of which powers are dealt with in the previous chapter. This is clear from the meaning of 'two years of days', that is, a period of two years, as a state involving a joining together; for 'two' means a joining together, 1686, 3519, while 'years' means states, as does 'days'. For the meaning of years' as states, see 487, 488, 493, 893, and for that of 'days', 27, 487, 488, 497, 2788, 3462, 3785, 4850. The reason 'two' means a joining together is that every single thing in the spiritual world, and consequently in the natural world, has two forces associated with it - goodness and truth. Good is an active inflowing force, truth a passive, recipient one. Also, because everything has these two forces associated with it, and because nothing can ever be brought forth unless the two are made one by becoming so to speak married to each other, a joining together is therefore meant by them.

[2] This type of marriage exists in every single thing within the natural order and its three kingdoms; without it nothing whatever can come into existence. For anything to come into existence within the natural order there needs to be heat and light, heat in the natural world corresponding to the good of love in the spiritual world, and light corresponding to the truth of faith. These two - heat and light - must act as one if anything is to be brought forth. If they do not act as one, as is the case in winter-time, nothing at all is brought forth. The same holds true on a spiritual level, as is quite evident with the human being, who has two mental powers - will and understanding. The will has been formed so that it may receive spiritual heat, that is, the good of love and charity, while the understanding has been formed so that it may receive spiritual light, that is, the truth of faith. Unless these two residing with a person make one nothing is brought forth, for the good of love devoid of the truth of faith cannot give definition and particular character to anything, while the truth of faith devoid of the good of love cannot bring anything into effect. So that the heavenly marriage may exist in a person therefore, or rather so that a person may be in the heavenly marriage, those two entities must make one in him. This explains why the ancients likened every single thing in the world, and every single thing within the human being, to a marriage, 54, 55, 568, 718, 747, 917, 1432, 2173, 2516, 2731, 2739, 2758, 3132, 4434, 4875, 5138. From all this one may see why it is that 'two' means a joining together.