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.

2180. 'And took a young bull, tender and good' means a celestial-natural which the rational took to itself in order that it might join itself to perception from the Divine. This is clear from the meaning of 'a young bull' or 'a son of an ox' in the Word as natural good. And because the subject is the Lord's Rational, it is called 'tender' from the celestial-spiritual, which is truth grounded in good, and 'good' from the celestial itself, which is good itself. Within the genuine rational there is both the affection for truth and the affection for good, but that which is first and foremost there is the affection for truth, as shown already in 2072. This explains why 'tender' is mentioned before 'good'; but even so, as is quite usual in the Word, both are mentioned on account of the marriage of truth and good which is referred to above in 2173.

[2] That 'a young bull' or 'a son of an ox' means the celestial-natural, or what amounts to the same, natural good, becomes especially clear from the sacrifices, which were the principal representatives in the worship of the Hebrew Church and after this of the Jewish Church. Their sacrifices were made either from the herd or from the flock, thus from animals of various kinds that were clean, such as oxen, young bulls, he-goats, sheep, rams, she-goats, kids, and lambs, besides doves and fledgling pigeons. All of these creatures meant the internal features of worship, that is, celestial and spiritual things, 2165, 2177, those from the herd meaning celestial-natural, those from the flock celestial-rational. Because both of these - natural things and rational things - are more and more interior and are various, so many genera and so many species of these creatures were therefore employed in sacrifices. This fact becomes clear also from its being laid down as to which creatures were to be offered in burnt offerings and also which in every kind of sacrifice - the daily sacrifices; those offered on sabbaths and at festivals; those made as free-will, eucharistic, or votive offerings; and those offered in purifications, cleansings, and also in inaugurations. Which creatures were to be used, and how many, in each kind of sacrifice is mentioned explicitly. This would never have been done unless each one had had some specific meaning, as is quite evident from those places where the sacrifices are the subject, as in Chapter 29 of Exodus; Chapters 1, 3, 4, 9, 16, and 23 of Leviticus; and Chapters 7, 8, 15, and 29 of Numbers. But this is not the place to explain what each one meant. The situation is similar in the Prophets where those animals are mentioned, from which it may become clear that young bulls meant celestial-natural things.

[3] That none but heavenly things were meant becomes clear also from the cherubim seen by Ezekiel and from the living creatures before the throne which were seen by John. Regarding the cherubim the prophet says,

The likeness of their faces was the face of a man (homo); and they four had the face of a lion on the right side; and they four had the face of an ox on the left side; and they four had the face of an eagle. Ezekiel 1:10.

Regarding the four living creatures before the throne John says,

Around the throne were four living creatures - the first living creature was like a lion, the second living creature like a young bull, the third living creature had a face like a man (homo), the fourth living creature was like a flying eagle - saying, Holy, holy, holy is the Lord God Almighty, who was, and who is, and who is to come. Revelation 4:7-8.

Anyone may see that holy things were represented by the cherubim and these living creatures, thus also by the oxen and young bulls in the sacrifices. The same applies in the prophecy of Moses concerning Joseph,

Let it come upon the head of Joseph and upon the crown of the head of the Nazirite among his brothers. The firstborn of his ox has honour, and his horns are the horns of a unicorn; with these he will thrust the peoples together, to the ends of the earth. Deuteronomy 33:16-17.

These words are not intelligible to anyone unless he knows what ox, unicorn, horns, and many other things mean in the internal sense.

[4] As for sacrifices in general they were indeed commanded to the Israelites through Moses. But the Most Ancient Church which existed before the Flood never knew anything at all about sacrifices, nor did it ever enter their minds to worship the Lord by the slaughtering of animals. The Ancient Church which existed after the Flood knew nothing about it either. Representatives did indeed exist there, but not sacrifices. These were first introduced in the subsequent Church called the Hebrew Church, and from there they spread to the gentile nations, and even to Abraham, Isaac, and Jacob, and so to Jacob's descendants. The fact that the gentile nations had sacrificial worship has been shown in 1343, and the fact that Jacob's descendants also had such worship before they left Egypt, thus before sacrifices were commanded through Moses on Mount Sinai, becomes clear from Exodus 5:3; 10:25, 27; 18:12; 24:4-5.

[5] This is especially clear from their idolatrous worship in front of the golden calf, regarding which the following is said in Moses,

Aaron built an altar in front of the calf, and Aaron made a proclamation and said, Tomorrow there will be a feast to Jehovah. And they rose up early the next morning and presented burnt offerings and brought peace offerings. And the people sat down to eat and drink, and rose up to play. Exodus 32:5-6.

This happened while Moses was on Mount Sinai, and so before the command came to them regarding the altar and the sacrifices. That command came to them for the reason that sacrificial worship among them had been turned, as it had among the gentiles, into idolatrous worship, from which they could not be drawn away because they looked upon it as-the chief holy thing. Once something has been implanted in people from their earliest years as being holy, the more so if received from their fathers, and thus is inrooted, the Lord in no way breaks it - provided it is not contrary to order itself - but bends it. This was the reason for its being laid down that the sacrificial system should be established, such as one reads in the books of Moses.

[6] The fact that sacrifices were by no means acceptable to Jehovah, and so were merely permitted and tolerated for the reason just stated, is quite evident in the Prophets. Concerning them the following is said in Jeremiah,

Thus said Jehovah Zebaoth, the God of Israel, Add your burnt offerings on to your sacrifices, and eat the flesh. I did not speak with your fathers and I did not command them on the day I brought them out of the land of Egypt on the matters of burnt offering and sacrifice. But this matter I commanded them, saying, Obey My voice, and I will be your God. Jeremiah 7:21-23.

In David,

O Jehovah, sacrifice and offering You have not desired; burnt offering and sin-sacrifices You have not sought. I have delighted to do Your will, O my God. Psalms 40:6, 8.

In the same author,

You do not delight in sacrifice that I should give it; burnt offering You do not accept. The sacrifices of God are a contrite spirit. Psalms 51:16-17.

In the same author,

I will not take any young bull from your house, nor he-goats from your folds. Sacrifice to God confession. Psalms 50:9, 14; 107:21-22; 116:17; Deuteronomy 23:18.

In Hosea,

I desire mercy and not sacrifice, and the knowledge of God rather than burnt offerings. Hosea 6:6.

Samuel said to Saul,

Has Jehovah great delight in burnt offerings and sacrifices? Behold, to be submissive is better than sacrifice, to be obedient than the fat of rams. - 1 Samuel 15:22.

In Micah,

With what shall I come before Jehovah and bow myself to God on high? Shall I come before Him with burnt offerings, with calves a year old? Will Jehovah be pleased with thousands of rams, with tens of thousands of rivers of oil? He has shown you, O man, what is good; and what does Jehovah require of you but to carry out judgement, and to love mercy, and to humble yourself by walking with your God? Micah 6:6-8.

[7] From these quotations it is now evident that sacrifices were not commanded but permitted, and also that in sacrifices nothing else was regarded except that which was internal, and that it was that which was internal that was pleasing, not that which was external. For this reason also the Lord abolished them, as was also foretold through Daniel in the following words when he was speaking about the Lord's Coming,

In the middle of the week He will cause the sacrifice and the offering to cease. Daniel 9:27.

See what has been stated about sacrifices in Volume One, in 922, 923, 1128, 1823. As for 'the young bull' which Abraham made ready or prepared for the three men, the meaning is similar to that of the same animals when used in sacrifices. That it had a similar meaning becomes clear also from the fact that he told Sarah to take three measures of fine flour. Regarding the fine flour that went with the offering of a young bull the following is said in Moses - referring to when they were to come into the land,

When you make ready a young bull for a burnt offering or a sacrifice in the declaring of a vow, or for peace offerings to Jehovah, you shall bring with the young bull a minchah of three tenths of fine flour mixed with oil. Numbers 15:8-9.

Here similarly the number 'three' appears, though three 'tenths' here but three 'measures' in Abraham's instruction to Sarah. But only two tenths went with the offering of a ram, one tenth with that of a lamb, Numbers 15:4-6.