527. "So that the day shone not for a third part of it, and the night likewise." - That these words signify that the spiritual light of truth and the natural light of truth were altogether extinguished, is evident from the signification of day, which denotes spiritual light, and from the signification of night, which denotes natural light. These things are signified, because it was said above, that the third part of the sun, the third part of the moon, and the third part of the stars, were darkened, and by day is meant the light of the sun, and by night, the light of the moon and stars, because the sun gives light during the day, and the moon and the stars give light in the night. Something shall first be said concerning light from the sun, which is called the light of the day, and concerning light from the moon and the stars, which is called the light of the night.
(References: Revelation 8:12)
 Light from the sun, which is called the light of the day, and also day, means spiritual light, such as the angels enjoy who see the Lord as a sun; and light from the moon and stars, called the light of the night, and also night, means natural light (lux naturalis), such as the angels enjoy who see the Lord as a moon. That the Lord appears to the angels as a sun, and also as a moon, may be seen in the Heaven and Hell (n. 116-125). Those heavens that are in the spiritual affection of truth, that is, who love truth because it is truth, behold the Lord as a sun; and because this is spiritual, therefore the light which is from the Lord as a sun is spiritual. But those heavens that are in the natural affection of truth, that is, who love truth in order to be learned and to instruct others, behold the Lord as a moon, these being in the love of it for the sake of what is useful for themselves, and not for the sake of truth itself, they are therefore in the light which proceeds from the Lord as a moon. This light differs from that which proceeds from the Lord as a sun, as the light of day from the sun differs from the light of the night from the moon and stars in our world. Just as the lights with them differ, so also do the truths, because the Divine Truth proceeding from the Lord is the cause of all light in the heavens; see in the Heaven and Hell (n. 126-140).
 Those therefore who are in spiritual light, are in genuine truths, and also when they hear truths, which they did not know before, they at once acknowledge them, and perceive that they are truths. It is different with those who are in natural light; these, when they hear truths, receive them because they are uttered by men of reputation, in whom they repose confidence, although they do not see and perceive [them to be truths]; most of these therefore are in faith from others, but still in a life according to faith. Into these heavens all those come who have lived well, although they have been in falsities of doctrine; nevertheless falsities are there continually purified, until at length they appear as truths. From these considerations the signification of the day shining not for a third part thereof, and the night likewise, is evident. That the third part signifies all, fulness and completeness, may be seen above (n. 506).
(References: The Apocalypse Explained 506)
 The signification of day and night here is similar to that of day and night in the first chapter of Genesis; where it is said:
"God said, Let there be light; and there was light. And God saw the light, that [it was] good; and God divided between the light and the darkness. And God called the light Day, and the darkness he called Night. And there was evening and there was morning the first day" (i. 3, 4, 5).
Afterwards it is said:
"And God said, Let there be luminaries in the expanse of the heavens to divide between the day and the night and they shall be for signs, and for seasons, and for days, and years. And God made two great luminaries; the great luminary to rule the day, and the lesser luminary to rule the night; and the stars. And God set them in the expanse of the heavens to give light upon the earth; and to rule over the day and over the night, and to divide between the light and between the darkness. And there was evening and there was morning, the fourth day" (i. 14-19).
The light which was made on the first day, signifies Divine light, which in itself and in its essence is Divine Truth, thus spiritual light, which enlightens the understanding. The subject treated of in that chapter, in the internal sense, is the establishment of a church by the Lord amongst the most ancient people. And because the understanding must first be enlightened, for without such enlightenment from the Lord there can be no reformation, consequently no church in man, therefore light is first spoken of, or it is said that there was light [lux] on the first day. The words "God saw the light, that it was good," signify that enlightenment and reception with them was good. But darkness signifies the light [lumen] which is in the natural man, which is also called natural light (lumen naturale); because this light compared with spiritual light (lux spiritualis) is like darkness, it is therefore meant by darkness.
For every man has a lower or exterior mind, and a higher or interior mind; the lower or exterior mind is the natural mind, and is called the natural man, but the higher or interior mind is the spiritual mind, and is called the spiritual man. The reason why the mind is called the man, is, because man is man by virtue of mind. These two minds, the higher and lower, are perfectly distinct. Man by means of the lower mind, is in the natural world, together with men there, but by means of the higher mind he is in the spiritual world with the angels there. These two minds are so distinct, that man while in the world does not know what takes place in his higher mind, and when he becomes a spirit, which is immediately after death, he does not know what takes place in his lower mind. It is therefore said that God divided between the light and between the darkness, and called the light day, and the darkness night. It is consequently evident that day signifies spiritual light (lux spiritualis), and darkness, natural light (lux naturalis). Because all the heavens are so distinct, that those who are in spiritual light may be in light from the Lord as a sun, and those who are in spiritual natural light may be in light from the Lord as a moon, as was said in the article above, it is therefore said, "Let there be two luminaries in the expanse of the heavens to divide between the day and between the night, and to rule in the day and in the night, and to divide between the light and the darkness." From these things, therefore, it is evident that by day is there meant spiritual light, and by night, natural light, which in heaven is called spiritual-natural light.
 Similar things are signified by day and night in the following passages.
Jehovah "who by understanding made the heavens, who spreadeth forth the earth above the waters, who made great luminaries, the sun to rule by day, the moon and stars to rule by night" (Psalm cxxxvi. 5-9).
So in Jeremiah:
"Jehovah giveth the sun for a light of the day, and the statutes of the moon and of the stars for a light of the night" (xxxi. 35).
Again, in David:
"The day is thine, Jehovah, the night also is thine; thou hast prepared the light and the sun" (Psalm lxxiv. 16).
And in Jeremiah:
"If ye shall have rendered void my covenant of the day, and my covenant of the night, and that there shall not be day and night in their season; my covenant also may be broken with David my servant, that he shall not have a son to reign upon his throne, and with the Levites the priests, my ministers. If I shall not have fixed my covenant of the day and of the night, and the statutes of the heaven and the earth; then cast I away the seed of Jacob and David" (xxxiii. 20, 21, 25, 26).
Here by the covenant of the day, and the covenant of the night, are meant all the statutes of the church, prescribed to the children of Israel in the Word, by means of which they had conjunction with heaven, and by means of heaven with the Lord. They are called the covenant of the day and of the night, because they are for heaven and also for the church, the spiritual things which are represented and signified being for heaven, and the natural things which are representative and significative being for the church. Therefore the covenants of the day and of the night are there called the statutes of the heaven and the earth, and the covenant of the night is called the statutes of the moon and stars; to render void, signifies not to keep. That no otherwise would there be conjunction with the Lord by the Divine Truth, nor by the Divine Good, is signified by, "My covenant with David my servant also shall not be broken, that he shall not have a son to reign upon his throne, and with the Levites the priests, my ministers." The covenant with David denotes conjunction with the Lord by means of the Divine Truth, no son upon his throne denotes no reception of the Divine Truth by any one, and the covenant with the Levites the priests, my ministers, denotes conjunction with the Lord by means of the Divine Good.
 So again, in David,
"If I say, Surely the darkness shall cover me; even the night shall be light for me. Yea, the darkness shall not make darkness before thee; but the night shall be as bright as the day; as the darkness so the light" (Psalm cxxxix. 11, 12).
These words signify that the natural man equally as the spiritual is enlightened by the Lord. Natural light is signified by darkness and night; and spiritual light, by light and day; "the night shall be as bright as the day, and as the darkness so the light" signifies the same as these words in Isaiah:
"The light of the moon shall be as the light of the sun" (xxx. 26).
These things are said in order that it may be known, that by the day which shone not for the third part of it, is signified spiritual light, and by the night which shone not in like manner, is signified natural light, thus that they have the same signification as light from the sun, and light from the moon.