In the third chapter of the Book of Jonah, Jonah finally reaches Nineveh, and starts preaching repentance and reformation to the people there. And... they listen! Even the King of Assyria listens!

The inner meaning of the story is pretty close to the surface here, and there's important symbolism. Swedenborg summarizes the chapter's meaning in this one sentence:

"The nations, hearing from the Word of God about their sins, and that they would perish, were converted after repenting, and were heard by the Lord, and saved." (The Inner Meaning of the Prophets and Psalms 213)

Rev. George McCurdy, in his exegesis of this chapter, offers this summary:

The great city of Nineveh has many spiritual representations. The world saw Nineveh as a mighty nation, but in the eyes of the Lord, it represented the shallowness and weakness (death) of false doctrines, contrived beliefs confirmed by the proprium (self love), the fallacies of the senses, and the unenlightened understanding that spawns spiritual ignorance.

The Lord’s mercy and love for all prompted Him not only to send His message to Nineveh, but to ensure that it would be preserved for eternity. Jonah’s call to "arise and go" preach to Nineveh is a call for spiritual renewal. It is a call for repentance. The fasting, sackcloth, and ashes symbolize a call to be aware that "where there is no truth, there is no church."

Where the Word is closed, and not loved, there is a loss of conjunction with the Divine resources. The fasting of man and beast symbolizes a need for the spiritual and natural appetites to come to the Lord for that "bread which comes down from heaven." The Ninevites giving up their natural food and drink represents their turning away from "as-of-self" concepts and reminds all who read and hear the Word of the Lord to rely on heavenly manna.

"Why do you spend money for what is not bread, and your wages for what does not satisfy? Listen carefully to Me and eat what is good, and let your soul delight itself in abundance…" (Isaiah 55:2)

The king sitting in ashes and mourning represents a sorrowful attitude toward "the remains of the fire of self-love." Repentance involves self-examination, making oneself guilty for the sins and evils committed, asking the Lord for His help, and desiring to attain a new life.

As we mull over this concept, think about the Lord’s preaching on earth. As He went about His mission, He often used these words: "You have heard it said of old… but I say unto you…" Putting aside human traditions and taking on the Lord’s teachings is an ongoing effort. Jonah was told to preach the words of the Lord. He was not to make things up from his memory. He was to be a true and faithful prophet of the Lord’s ways.

Here's a link to an interesting (audio) sermon on this chapter, by Rev. Todd Beiswenger.

Rev. Martin Pennington suggests two explanatory passages from Swedenborg's theological writings:

"Forty days means a period of temptation combats or severe change." (Arcana Coelestia 730)

"A fast represents those who are in a state of unhappiness when good is no longer joined to the truths." (Arcana Coelestia 9182[10])

Other references of interest listed by Rev. McCurdy include:

"As ‘forty’ signified what is full or complete… forty signifies what is complete in respect to instruction and influx… for this reason it was said by Jonah to the Ninevites that ‘the city would be overthrown after forty days" (Jonah 3:4) (Arcana Coelestia 9437[2])

"By being clothed in sackcloth is signified mourning on account of the vastated truth in the church; for garments signify truths; and therefore, to be clothed in sackcloth, which is not a garment, signifies mourning that there is no truth; and where there is no truth, there is no church." Jonah 3:5-6 is cited. (Apocalypse Revealed 492)

"…the rite of putting sackcloth on the loins to testify…mourning may be seen from the historic and prophetic parts of the Word, as in… Jonah 3:5-8… for a sign representative of mourning over the evil on account of which Nineveh was to perish; thus over destroyed good." (Arcana Coelestia 4779[2])

"From the signification of garments it is also manifest why they rent their garments, when any one spoke against the Divine truth of the Word… and why, on account of transgressions against Divine truths, they put off their garments, and put on sackcloth." Jonah 3:5, 6, and 8 are cited. (Apocalypse Revealed 166)

"That ‘ashes’ denote falsity, may be confirmed from passages where another word for ‘ashes (cinis)’ is used, for these ashes have a like origin…" Jonah 3:6 is cited. (Arcana Coelestia 7520)

"…by ‘ashes’ in the opposite sense, namely, what is condemned that remains after the burning from the fire of self love. This is signified by ‘the ashes’ which they carried on the head, and in which they rolled themselves when bewailing their sins." Jonah 3:6 is cited. (Arcana Coelestia 9723)

"In the spiritual sense by kings those who are in truths are signified, by the great ones those who are in goods, by the rich those that are in the knowledge of good, by the mighty they that are in erudition, by servants they that are in such things from others, and thus from memory, and by freemen they that are in such things from themselves…" Jonah 3:7 is cited. (Apocalypse Revealed 337)

"The interior good and also the interior evil…are signified by ‘man,’ are those which are of the intention or end, for the intention or end is the inmost of man; but the exterior good and also the exterior evil which are signified by ‘beast,’ are those which are of the thought, and of the consequent action when nothing stands in the way…By ‘beast,’…in respect to the external or natural man, a man is nothing else than a beast, for he takes delight in the like cupidities and pleasures, as also in the like appetites and sense…Therefore… from a holy rite it was commanded by the king of Nineveh, that both man and beast were to fast, and were to be covered with sackcloth (Jonah 3:7, 8)." (Arcana Coelestia 7523)

"… in the spiritual world a man’s affections appear at a distance like beasts… and beasts, viewed in themselves, are nothing but forms of natural affections… By man and beasts together is signified man as to spiritual and natural affection, in the following passages… Jonah 3:7, 8…" (Apocalypse Revealed 567)

"Here ‘webs’ and ‘garments’ are predicated of things of the understanding, that is, of the thought; ‘iniquity’ and ‘violence,’ of things of the will, that is, of works. In Jonah 3:8… the ‘evil way’ is predicated of falsities, which are of the understanding; and ‘violence,’ which are of the will." (Arcana Coelestia 623[2])

"…the ‘wrath of anger’ is attributed to Jehovah, and consequently ‘repentance.’" (Arcana Coelestia 588[2])

"…the Word is such in the sense of the letter, it may be evident that it cannot be understood without doctrine. But let examples illustrate this. It is said that Jehovah repenteth (Jonah 3:9; 4:2), and it is also said that Jehovah repenteth not (Num. 23:19…): without doctrine these statements do not agree." (Teachings Regarding the Sacred Scripture 51)

"In these passages (Jonah 3:9,10) Jehovah is said to have ‘repented,’ when yet it cannot be that He repents, because He knows all things before He does them; from which it is evident that by ‘repenting’ is signified mercy." (Arcana Coelestia 10441[2-4])

Finally, here's a link to Rev. McCurdy's study guide for the Book of Jonah, which is available for free as a .pdf, for your use.

408. Verse 15. And the kings of the earth, and the great ones, and the rich, and the commanders of thousands, and the mighty, signify all internal goods and truths, and all external goods and truths, by means of which there are wisdom and intelligence. This is evident from the signification of "kings," as being truths from good in their whole complex (of which above, n. 31; from the signification of "great ones, and the rich," as being internal goods and truths (of which presently); from the signification of "commanders of thousands and the mighty" as being external goods and truths; "commanders of thousands" meaning such goods, and "the mighty" such truths (of which also presently). It is added, "by means of which there are wisdom and intelligence," because from internal goods and truths, which are spiritual goods and truths, there is wisdom, and from external goods and truths, which are natural goods and truths from spiritual, there is intelligence. Wisdom differs from intelligence in this, that wisdom is from the light of heaven, and intelligence from the light of the world enlightened by the light of heaven; this is why wisdom is predicated of spiritual goods and truths, and intelligence of natural goods and truths; for spiritual goods and truths are from the light of heaven, because the spiritual mind or the internal mind is in the light of heaven; and natural goods and truths are from the light of the world, because the natural or external mind is in the light of the world; but so far as this mind receives the light of heaven through the spiritual mind, so far it is in intelligence. He who believes that intelligence is from the light of the world only, which is called natural light, is much deceived. Intelligence means seeing from oneself truths and goods, whether civil, moral, or spiritual, while seeing them from another is not intelligence but knowledge [scientia]. Yet that it may be known how these things are to be understood, see what is said in a preceding article n. 406, namely, that man has two minds, the one spiritual or internal, the other natural or external, and that the spiritual or internal mind is opened with those who apply the goods and truths of the Word to the life, while in those who do not apply the goods and truths of the Word to the life, that mind is not opened, but only the natural or external mind; such are thence called natural men, but the former spiritual.

To this let it be added, that so far as the spiritual or internal mind is opened, spiritual light, which is the light of heaven, flows in through it from the Lord into the natural or external mind, and enlightens that mind and gives intelligence. The goods and truths that constitute the spiritual or internal mind are meant by "the great ones and the rich," goods by "the great ones," and truths by "the rich;" and the goods and truths that constitute the natural or external mind are meant by "the commanders of thousands and the mighty," these goods by "the commanders of thousands," and these truths by "the mighty." This makes clear that these words, in the internal sense, include all things that are with man; for the extinction of all these is treated of in what follows. All things with man as well as all things in the universe have reference to good and truth; it is from these and according to these that man has all wisdom and intelligence.

[2] He who looks only to the sense of the letter cannot see otherwise than that kings and the chief men in their kingdoms are here meant, and that so many are mentioned in order to exalt that sense; but in the Word no word is meaningless, for the Divine is in all things and in everything of the Word. So these must mean things Divine, which are of heaven and the church, and which are called, in general, celestial and spiritual, and from these the Word is Divine, celestial, and spiritual. Moreover, the Word was given that by it there may be conjunction of heaven with the church, or of the angels of heaven with the men of the church (See in the work on Heaven and Hell 303-310); and such conjunction would not be possible if nothing else were meant by these words than what stands forth in the sense of the letter, namely, that the kings of the earth, the great ones, the rich, the commanders of thousands, and the mighty, as also every servant and every freeman, were to hide themselves in caves and in the rocks of the mountains, for these are natural things; but when spiritual things are at the same time understood by these there is conjunction. In no other way could angels be conjoined with men, for the angels are spiritual because they are in the spiritual world and thus both think spiritually and speak spiritually; while men are natural, because they are in the natural world, and thence think naturally and speak naturally. This is said to make known that "the kings of the earth, the great ones, the rich, the commanders of thousands, and the mighty," signify also things spiritual. That these mean spiritual things, namely, "the great ones and the rich" internal goods and truths, and "the commanders of thousands and the mighty" external goods and truths, can be seen from their signification where they are mentioned in the Word.

[3] "Great ones" in the Word signify internal goods which are the goods of the internal or spiritual man, because "great" and "greatness" in the Word are predicated of good, and "many" and "multitude" of truth (See above, n. 336, 337). Internal goods are signified by "great ones," because these four, namely, "great ones," "the rich," "the commanders of thousands" and "the mighty" signify all the goods and truths that are with man, thus the goods and truths both of the internal or spiritual man and of the external or natural man; "the great ones and the rich" meaning the goods and truths of the internal or spiritual man, and "the commanders of thousands and the mighty" the goods and truths of the external or natural man; so it is added, "every servant and every freeman," "servant" signifying the external of man, which is called the natural man, and "freeman" the internal of man, which is called the spiritual man. Like things are signified by "great ones" elsewhere in the Word (namely in Jeremiah 5:5; in Nahum 3:10; and in Jonah 3:7).

That "the rich" signify internal truths, which are spiritual truths or those who are in such truths, is evident from what has been shown above (n. 118, 236). That "the commanders of thousands" signify external goods, which are the goods of the natural man, has also been shown above (n. 336); it is therefore unnecessary to say more respecting these. But that "the mighty" signify external truths, or truths of the natural man, is evident from many passages in the Word, where "the mighty" and "the strong," likewise "power" and "strength" are mentioned; this is because truths from good, and indeed truths that are in the natural man, have all power. Truths from good are what have all power, because good does not act of itself, but by truths, for good forms itself in truths, and clothes itself with them, as the soul does with the body, and so acts; it acts by truths in the natural man, because there all interior things are together, and in their fullness. (That truths from good, or good by means of truths, has all power may be seen above, n. 209, 333; and in the work on Heaven and Hell 231, 232, 539; and that all power is in ultimates, because the Divine is there in its fullness, see above, n. 346; and Arcana Coelestia 9836, 10044.) From this it can be seen that "the mighty" mean external truths, or truths of the natural man.