Selection from Apocalypse Explained ~ Emanuel Swedenborg
The "harvest" signifies the last state of the church - when the old church has been laid waste, that is, when there is no longer any truth or good left in it that has not been falsified or cast aside.
In Joel:
The husbandmen were ashamed, the vine-dressers howled for the wheat and for the barley, because the harvest of the field hath perished (1:11).
The devastation of the church as to good and truth is here meant by "the harvest of the field hath perished;" "husbandmen" mean those who are in the good of the church, and "vine-dressers" those who are in its truths; "wheat and barley" mean good itself and truth itself; grief on account of devastation is signified by "they were ashamed and howled."
"Harvest" signifies the last state of the church, because "corn," which is the harvest, signifies the good of the church and truth from good, and "field" the church itself. That all things pertaining to natural nourishment, such as wheat, barley, oil, wine, and the like, signify such things as pertain to spiritual nourishment; and the things that pertain to spiritual nourishment have reference in general to good and truth and knowledges of them, thus to doctrine and to a life according to these knowledges.
Therefore it is said in Jeremiah:
A nation from afar shall eat up thy harvest and thy bread, it shall eat up thy sons and thy daughters, it shall eat up thy flock and thy herd, it shall eat up thy vine and thy fig-tree; it shall impoverish thy fortified cities, in which thou dost trust, with the sword (5:17).
"A nation from afar" means the falsity of evil destroying; "from afar" signifying what is far away from good and truth. "Harvest" and "bread" signify nourishing truths and goods of the church; "sons and daughters" goods and truths generating; "flock and herd" goods and truths spiritual and natural, "vine and fig-tree" the internal spiritual church, and the external natural church; the "fortified cities in which they trust" signify doctrinals from self-intelligence; "to be impoverished with the sword" signifies to be destroyed by falsities of evil.
As "harvest" signifies all things that spiritually nourish man, and these have reference to the truths of doctrine and the goods of life, so "harvest" signifies the church in general and in particular; in general, in these words in the Gospels:
Jesus said to His disciples, The harvest is plenteous but the laborers are few; pray ye, therefore, the Lord of the harvest that He send laborers into His harvest (Matt. 9:37, 38; Luke 10:2).
The "harvest" here means all with whom the church was to be established by the Lord, thus also the church in general; and "laborers" mean all who will teach from the Lord.
Likewise in John:
Jesus said to the disciples, Say ye not there are yet four months and then cometh the harvest? Behold I say unto you, Lift up your eyes and look on the fields that they are white already for harvest. And he that reapeth receiveth reward and gathereth fruit unto life eternal. For herein is the saying true, that there is one who soweth and another who reapeth. I sent you to reap that whereon ye have not labored; others have labored, but ye have entered into their labor (4:35-38).
The increase of the church with man in particular, and with men in general by the Lord, is also described by "harvest" in Mark:
Jesus said, So is the kingdom of God as if a man should cast seed upon the earth, and should then sleep and rise night and day, and the seed should spring up and grow up he knoweth not how. For the earth beareth fruit of herself, first the blade, then the ear, then the full corn in the ear. But when the fruit hath come forth straightway he putteth forth the sickle, because the harvest is ready (4:26-29).
"The kingdom of God" means the church of the Lord in the heavens and on the earth; and the implantation of it with all who receive truths and goods from the Lord, not from self, is described by these words, every particular of which corresponds to spiritual things and signifies them; as that "a man casts seed upon the earth, that he then sleeps, and rises night and day, that the seed springs up and grows up he knows not how;" for "seed" signifies the Divine truth, "to cast seed into the earth" signifies the work of man, "to rise day and night" and finally "to put in the sickle" signifies in every state. The rest signifies the Lord's work; and the "harvest" the implantation of the church in particular and in general.
For it is to be known, that, although the Lord works all things, and man nothing from self, yet He wills that man should work as if from self in all that comes to his perception. For without man's cooperation as if from self there can be no reception of truth and good, thus no implantation and regeneration. For to will is the Lord's gift to man; and because the appearance to man is that this is from self, He gives him to will as if from self.Such being the signification of "harvest" two feasts were instituted with the sons of Israel, one of which was called the feast of seven weeks, which was that of the harvest of firstfruits; and the other the feast of tabernacles, which was the feast of ingathering of the fruits of the earth. Of these the first signified the implantation of truth in good, and the other the bringing forth of good, thus regeneration. But the feast of unleavened bread, or the Passover, which preceded, signified deliverance from the falsities of evil, which is the first thing of regeneration.
(from Apocalypse Explained 911)