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.

10122. 'And a young bull of sin [offering] you shall offer daily at propitiations' means the continuous removal of evils and consequently of falsities in the natural man by means of the good of innocence from the Lord. This is clear from the meaning of 'a young bull' as the good of innocence in the natural man, dealt with in 9391, 9990; from the meaning of 'sin' as purification from evils and consequently falsities (by 'sin' a sacrifice for sin should be understood, 10039, and 'a sin sacrifice' means purification from evils and falsities, 9938, 9990, 10022, 10053), the reason for saying 'the removal' of evils and consequently of falsities being that the evils and falsities with a person are not cast out, only removed or moved back, see the places referred to in 10057; from the meaning of 'daily' or each day as continuously; and from the meaning of 'propitiations' as reception of the good of love and truth of faith from the Lord after the removal of evils and consequently of falsities, dealt with in 9506.

[2] The words 'removal of evils and consequently of falsities' are used because all falsities exist as a result of evil; therefore to the extent that evil is removed falsities are removed. The situation is that all things in heaven have connection with good and consequently with truth, and all things in hell with evil and consequently with falsity. The same is so in people. All the things with a person that come from heaven have connection with good and truth, and all those that come from hell have connection with evil and falsity. Or what amounts to the same thing, all things with a person which originate in the Lord have connection with good and truth, but all that originate in the person himself have connection with evil and falsity. Since good and truth or falsity and evil are what everything throughout creation has connection with, and the human being is the place where they are received, a person has two mental powers to receive them. One is called the will and the other the understanding, the will being what receives good or evil, and the understanding what receives truth or falsity. The will formed by the Lord, also called the new will, receives good, while the understanding formed by the Lord, also called the new understanding, receives truth. But the will properly a person's own, also called the old will, receives evil, and the understanding properly a person's own, also called the old understanding, receives falsity. A person possesses the old will and understanding through being born from his parents, but he comes to have the new will and understanding through being born from the Lord, which happens when he is being regenerated. For when being regenerated a person is conceived anew and is born anew.

[3] The human being has been created in such a way that will and understanding may make one, so that these two together may constitute a whole person. For a person has been given an understanding to comprehend truth, yet to the end that truth may be implanted in his will and become good. And to the extent that it is integrated into the will it has a place in that person; for the will is the inmost part of a person and is the inner being of his life, whereas the understanding is more external and derives its being from the will. For what a person wills he loves, and what he loves gives him a feeling of delight and is therefore called good by him. The understanding lends support to and strengthens it by means of reasons which it calls truths. So it is that will and understanding in reality make one. The situation may indeed seem to be other than this, as when a person understands the truth and yet wills what is evil; even so, when he is left alone to think for himself, what he understands is in full agreement with what he wills, that is, what he loves.

[4] The fact that a person who wills what is evil can nevertheless speak what is true and also do what is good is due to hypocrisy, which uses truth and good as means to its own ends. If those means are taken away from such a person and he is left in freedom, he plunges, under the influence of his unrestrained will, into evils, and uses his power of understanding to defend them. This is above all evident from the same kind of people in the next life. There everyone comes into a state [of life] akin to that of his will, and then people in whom a new will has not been formed by the Lord plunge into evils of every kind and think such things as endorse evils, even though what they had spoken and what they had done in the world had been completely different from this. For it is a law of Divine order that will and understanding should form a mind at unity, thus a person at unity, consequently that the entire person should be either in heaven or in hell and not hanging between the two, that is, with his eye looking towards the things of heaven and his heart set on those of hell. By heart is meant the will, and by eye the understanding.