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.

4835. 'Come [in] to your brother's wife and perform the duty of a husband's brother to her' means that this - that representative of the Church - might be continued. This is clear from the meaning of 'coming (or going in) to a brother's wife and performing the duty of a husband's brother to her' as preserving and continuing that which constitutes the Church. The requirement laid down in the Mosaic Law, that if a man died without issue his brother was to marry his widow and raise up seed for his brother, and that the firstborn was to receive his dead brother's name, whereas all other sons were to be his own, was called the duty of a brother-in-law. The fact that this directive was nothing new in the Jewish Church but a practice already in existence is clear from the words used here; and the same goes for many other directives given to the Israelites through Moses, such as the law forbidding them to take wives from the daughters of the Canaanites and requiring them to marry within their own families, Genesis 24:3-4; 28:1-2. From these and many other examples it is evident that a Church had existed previously in which the same kind of practices were followed as those at a later time which were declared to and demanded of the sons of Jacob. Altars and sacrifices likewise had been in use since ancient times, as is evident from Genesis 8:20-21; 22:3, 7-8. From this it is plain that the Jewish Church was not a new Church but a revival of the Ancient Church which had perished.

[2] What the law regarding the duty of a brother-in-law had been is clear in Moses,

If brothers dwell together but one of them dies, and has no son, the wife of the dead one shall not marry a stranger outside [the family]; her brother-in-law shall go in to her, and take her to himself as his wife, and so perform the duty of a brother-in-law to her. Then it will happen, that the firstborn whom she bears shall succeed to the name of his dead brother, so that his name is not wiped out from Israel. But if the man is unwilling to take his sister-in-law, his sister-in-law shall go up to the gate to the elders, and she shall say, My brother-in-law refuses to raise up for his brother a name in Israel; he is unwilling to perform the duty of a brother-in-law for me. Then the elders of his city shall call him and speak to him; and if he stands and says, I do not desire to take her, his sister-in-law shall go up to him in the sight of the elders, and she shall remove his shoe from upon his foot and spit in his face; and she shall answer and say, So will it be done to the man who does not build up his brother's house. Therefore his name will be called in Israel, The house of him who has his shoe taken off. Deuteronomy 25:5-10.

[3] Anyone who does not know what the duty of a brother-in-law represents inevitably believes that the practice existed solely for the sake of preserving a name and consequently an inheritance. But the preservation of a name and an inheritance was not in itself a great enough reason why a brother should have been required to enter into a marriage with his sister-in-law. Rather, the practice was ordained so that the preservation and continuation of the Church might be represented through it. For a marriage represented the marriage of good and truth, which is the heavenly marriage. It therefore represented the Church too, for the Church is a Church by virtue of the marriage of good and truth, and when this marriage exists within it the Church makes one with heaven, which is the true heavenly marriage. And because a marriage represented these things, 'sons and daughters' were therefore representations and also meaningful signs of truths and goods. This being so, 'being without issue' meant a lack of good and truth, and so meant that no representative of the Church existed in that house any longer, and that as a consequence it was not in communion with the Church. In addition 'brother' represented a kindred good to which the truth represented by a widow might be joined. For to be the kind of truth that has life, produces fruit, and thereby continues that which constitutes the Church, truth cannot be joined to any other good but that which is its own and a kindred one. This was how those in heaven perceived the duty of a brother-in-law.

[4] The meaning of this practice - of a sister-in-law removing the shoe from upon the foot of the man who refused to do the duty of a brother-in-law, and of her spitting in his face - was this: Anyone devoid of good and truth, external and internal, would destroy those things that constitute the Church; for 'the shoe' means that which is external, 1748, and 'the face' that which is internal, 1999, 2434, 3527, 4066, 4796. From this it is evident that 'the duty of a brother-in-law' represented the preservation and continuation of the Church. But when through the Lord's Coming representatives of internal things came to an end, that particular law was done away with. It is like a person's soul or spirit in relation to his body. A person's soul or spirit is the internal part of him and his body the external; or what amounts to the same, the soul or spirit is the true likeness of the person, whereas the body is merely a representative image of him. When a person rises again his representative image or that which is external, namely his body, is cast aside, for he is now conscious in that which is internal, namely the true likeness of him. It is also like a person who is in darkness and from there looks at things belonging to light; or what amounts to the same, like one who is in the light of the world and from there looks at things belonging to the light of heaven. For the light of the world in comparison with the light of heaven is as darkness. Within that darkness, that is, within the light of the world, things belonging to the light of heaven as they exist essentially cannot be seen, but are seen so to speak within a representative image, even as the human mind is seen in a person's face. Therefore when the light of heaven is seen in its own essential brightness, the darkness of representative images is dispelled. This was effected through the Lord's Coming.

[4835a] 'And raise up seed for your brother' means so that the Church does not perish. This is clear from the meaning of 'seed' as truth derived from good, or faith grounded in charity, dealt with in 1025, 1447, 16110, 1940, 2848, 3310, 3373, 3671. The same is also meant by the firstborn who was to succeed to the name of the dead brother, 352, 367, 2435, 3325, 3494. 'Raising up seed for a brother' means continuing that which constitutes the Church, in line with what has been stated just above in 4834, and thus means so that the Church does not perish.