Teshuvah
(א) וַיְמַ֤ן יְהוָה֙ דָּ֣ג גָּד֔וֹל לִבְלֹ֖עַ אֶת־יוֹנָ֑ה וַיְהִ֤י יוֹנָה֙ בִּמְעֵ֣י הַדָּ֔ג שְׁלֹשָׁ֥ה יָמִ֖ים וּשְׁלֹשָׁ֥ה לֵילֽוֹת׃ (ב) וַיִּתְפַּלֵּ֣ל יוֹנָ֔ה אֶל־יְהוָ֖ה אֱלֹהָ֑יו מִמְּעֵ֖י הַדָּגָֽה׃ (ג) וַיֹּ֗אמֶר קָ֠רָאתִי מִצָּ֥רָה לִ֛י אֶל־יְהוָ֖ה וַֽיַּעֲנֵ֑נִי מִבֶּ֧טֶן שְׁא֛וֹל שִׁוַּ֖עְתִּי שָׁמַ֥עְתָּ קוֹלִֽי׃ (ד) וַתַּשְׁלִיכֵ֤נִי מְצוּלָה֙ בִּלְבַ֣ב יַמִּ֔ים וְנָהָ֖ר יְסֹבְבֵ֑נִי כָּל־מִשְׁבָּרֶ֥יךָ וְגַלֶּ֖יךָ עָלַ֥י עָבָֽרוּ׃ (ה) וַאֲנִ֣י אָמַ֔רְתִּי נִגְרַ֖שְׁתִּי מִנֶּ֣גֶד עֵינֶ֑יךָ אַ֚ךְ אוֹסִ֣יף לְהַבִּ֔יט אֶל־הֵיכַ֖ל קָדְשֶֽׁךָ׃ (ו) אֲפָפ֤וּנִי מַ֙יִם֙ עַד־נֶ֔פֶשׁ תְּה֖וֹם יְסֹבְבֵ֑נִי ס֖וּף חָב֥וּשׁ לְרֹאשִֽׁי׃ (ז) לְקִצְבֵ֤י הָרִים֙ יָרַ֔דְתִּי הָאָ֛רֶץ בְּרִחֶ֥יהָ בַעֲדִ֖י לְעוֹלָ֑ם וַתַּ֧עַל מִשַּׁ֛חַת חַיַּ֖י יְהוָ֥ה אֱלֹהָֽי׃ (ח) בְּהִתְעַטֵּ֤ף עָלַי֙ נַפְשִׁ֔י אֶת־יְהוָ֖ה זָכָ֑רְתִּי וַתָּב֤וֹא אֵלֶ֙יךָ֙ תְּפִלָּתִ֔י אֶל־הֵיכַ֖ל קָדְשֶֽׁךָ׃ (ט) מְשַׁמְּרִ֖ים הַבְלֵי־שָׁ֑וְא חַסְדָּ֖ם יַעֲזֹֽבוּ׃ (י) וַאֲנִ֗י בְּק֤וֹל תּוֹדָה֙ אֶזְבְּחָה־לָּ֔ךְ אֲשֶׁ֥ר נָדַ֖רְתִּי אֲשַׁלֵּ֑מָה יְשׁוּעָ֖תָה לַיהוָֽה׃ (ס) (יא) וַיֹּ֥אמֶר יְהוָ֖ה לַדָּ֑ג וַיָּקֵ֥א אֶת־יוֹנָ֖ה אֶל־הַיַּבָּשָֽׁה׃ (פ)

(1) And the LORD prepared a great fish to swallow up Jonah; and Jonah was in the belly of the fish three days and three nights. (2) Then Jonah prayed unto the LORD his God out of the fish’s belly. (3) And he said: I called out of mine affliction Unto the LORD, and He answered me; Out of the belly of the nether-world cried I, And Thou heardest my voice. (4) For Thou didst cast me into the depth, In the heart of the seas, And the flood was round about me; All Thy waves and Thy billows Passed over me. (5) And I said: ‘I am cast out From before Thine eyes’; Yet I will look again Toward Thy holy temple. (6) The waters compassed me about, even to the soul; The deep was round about me; The weeds were wrapped about my head. (7) I went down to the bottoms of the mountains; The earth with her bars closed upon me for ever; Yet hast Thou brought up my life from the pit, O LORD my God. (8) When my soul fainted within me, I remembered the LORD; And my prayer came in unto Thee, Into Thy holy temple. (9) They that regard lying vanities Forsake their own mercy. (10) But I will sacrifice unto Thee With the voice of thanksgiving; That which I have vowed I will pay. Salvation is of the LORD. (11) And the LORD spoke unto the fish, and it vomited out Jonah upon the dry land.

תנן התם רבי אליעזר אומר שוב יום אחד לפני מיתתך שאלו תלמידיו את ר"א וכי אדם יודע איזהו יום ימות אמר להן וכל שכן ישוב היום שמא ימות למחר ונמצא כל ימיו בתשובה
We learned there in a Mishnah, Rebbe Eliezer says Repent (do teshuva) one day before your death The students of Rebbe Eliezer asked him But does a person know which day he will die He said to them All the more so, Let a person repent today, he may die tomorrow, and he will find all his days in penitence
א,א כָּל הַמִּצְווֹת שֶׁבַּתּוֹרָה, בֵּין עֲשֵׂה בֵּין לֹא תַעֲשֶׂה--אִם עָבַר אָדָם עַל אַחַת מֵהֶן, בֵּין בְּזָדוֹן בֵּין בִּשְׁגָגָה--כְּשֶׁיַּעֲשֶׂה תְּשׁוּבָה וְיָשׁוּב מֵחֶטְאוֹ, חַיָּב לְהִתְוַדּוֹת לִפְנֵי הָאֵל בָּרוּךְ הוּא: שֶׁנֶּאֱמָר "אִישׁ אוֹ-אִשָּׁה כִּי יַעֲשׂוּ מִכָּל-חַטֹּאת הָאָדָם . . . וְהִתְוַדּוּ, אֶת-חַטָּאתָם אֲשֶׁר עָשׂוּ" (במדבר ה,ו-ז), זֶה וִדּוּי דְּבָרִים. וּוִדּוּי זֶה מִצְוַת עֲשֵׂה.
All of the Mitzvot in the Torah: whether they be the positive commandments, or the negative commandments; if a person transgressed any of them, whether he did so willingly, whether he did so unintentionally, when he does Teshuva and returns from sinning- he is obligated to confess before Hashem. As it says in the Pasuk: "When a man or women commits any of the forbidden actions of man,...and he shall confess his sin that he committed", the confession we are dealing with is a verbal confession. Confession is a positive commandment.

(ג) ב,ג [ב] וּמַה הִיא הַתְּשׁוּבָה--הוּא 1שֶׁיַּעֲזֹב הַחוֹטֶא חֶטְאוֹ, וִיסִירֶנּוּ מִמַּחְשַׁבְתּוֹ 2וְיִגְמֹר בְּלִבּוֹ שֶׁלֹּא יַעֲשֵׂהוּ עוֹד, שֶׁנֶּאֱמָר "יַעֲזֹב רָשָׁע דַּרְכּוֹ, וְאִישׁ אָוֶן מַחְשְׁבֹתָיו" (ישעיהו נה,ז). וְכֵן 3יִתְנַחַם עַל שֶׁעָבַר, שֶׁנֶּאֱמָר "כִּי-אַחֲרֵי שׁוּבִי, נִחַמְתִּי, וְאַחֲרֵי הִוָּדְעִי, סָפַקְתִּי עַל-יָרֵךְ" (ירמיהו לא,יח); וְיָעִיד עָלָיו יוֹדֵעַ תַּעֲלוּמוֹת שֶׁלֹּא יָשׁוּב לְזֶה הַחֵטְא לְעוֹלָם, שֶׁנֶּאֱמָר "וְלֹא-נֹאמַר עוֹד אֱלֹהֵינוּ, לְמַעֲשֵׂה יָדֵינוּ--אֲשֶׁר-בְּךָ, יְרֻחַם יָתוֹם" (הושע יד,ד). וְצָרִיךְ 4לְהִתְוַדּוֹת בִּשְׂפָתָיו, וְלוֹמַר עִנְיָנוֹת אֵלּוּ שֶׁגָּמַר בְּלִבּוֹ.

(3) What is teshuvah? It is when a person 1abandons the sin that he sinned and removes it from his thoughts 2and commits in his heart that he will not do it again, as it says, The wicked should abandon his path etc. (Isaiah 55:7). And also 3that he regrets sinning, as it says, After I returned I regretted (Jeremiah 31:18). And the One Who Knows Hidden Things testifies about him that he will never return to this sin, as it says, And we will no longer call the work of our hands “god” etc. (Hosea 14:4). 4And he must confess verbally and say these things that he has committed in his heart.

(יד) וַיֹּ֤אמֶר אֱלֹהִים֙ אֶל־מֹשֶׁ֔ה אֶֽהְיֶ֖ה אֲשֶׁ֣ר אֶֽהְיֶ֑ה וַיֹּ֗אמֶר כֹּ֤ה תֹאמַר֙ לִבְנֵ֣י יִשְׂרָאֵ֔ל אֶֽהְיֶ֖ה שְׁלָחַ֥נִי אֲלֵיכֶֽם׃

(14) And God said unto Moses: "Ehyeh Asher Ehyeh" (I AM THAT I AM); and God said: ‘Thus shall you say unto the children of Israel: I AM (Ehyeh) hath sent me unto you.’

(ד) ב. ועקר התשובה כשישמע בזיונו, ידם וישתק... בחינת אהיה, בחינת תשובה,

(ה) כי אהיה דא אנא זמין למהוי. הינו קדם התשובה, עדין אין לו הויה, כאילו עדיין לא נתהוה בעולם, כי טוב לו שלא נברא משנברא, וכשבא לטהר את עצמו ולעשות תשובה, אז הוא בבחינת אהיה, הינו שיהיה לו הויה בעולם, הינו אנא זמין למהוי.

אבל קדם התשובה אזי בחינת אהיה בהסתרת פנים ממנו, כי עדין לא הכין את עצמו למהוי בעולם.

The essence of teshuvah is that when a person hears themselves being insulted, they remain quiet and silent...

This corresponds to Ehyeh, which corresponds to teshuvah.

For the meaning of Ehyeh is "I am prepared to be." That is, before teshuvah a person does not yet have a being. It is as if they do not yet exist in the world. Indeed, [if this is the case] it [may be] better off if they had not been created. But when a person prepares to purify and do teshuvah, they are then in the aspect of ehyeh. In other words, he will then exist in the world--i.e. "I am prepared to be."

Before teshuvah, however, the aspect of ehyeh is hidden from him. For he has not yet prepared himself to exist in the world.

Rambam Mishneh Torah, Hilchos Teshuva Perek 2
Halacha 1

[Who has reached] complete Teshuvah? A person who confronts the same situation in which he sinned when he has the potential to commit [the sin again], and, nevertheless, abstains and does not commit it because of his Teshuvah alone and not because of fear or a lack of strengthFor example, a person engaged in illicit sexual relations with a woman. Afterwards, they met in privacy, in the same country, while his love for her and physical power still persisted, and nevertheless, he abstained and did not transgress. This is a complete Baal-Teshuvah.

"Remember your Creator in the days of your youth, [before the bad days come and the years draw near when you will say: `I have no desire for them.'"}If he does not repent until his old age, at a time when he is incapable of doing what he did before, even though this is not a high level of repentance, he is a Baal-Teshuvah.

Even if he transgressed throughout his entire life and repented on the day of his death and died in repentance, all his sins are forgiven as [Ecclesiastes, op. cit.:2] continues: "Before the sun, the light, the moon, or the stars are darkened and the clouds return after the rain..." - This refers to the day of death. Thus, we can infer that if one remembers his Creator and repents before he dies, he is forgiven.

Halacha 2

What constitutes Teshuvah? That a sinner should abandon his sins and remove them from his thoughts, resolving in his heart, never to commit them again as [Isaiah 55:7] states "May the wicked abandon his ways...." Similarly, he must regret the past as [Jeremiah 31:18] states: "After I returned, I regretted."

[He must reach the level where] He who knows the hidden will testify concerning him that he will never return to this sin again as [Hoshea 14:4] states: "We will no longer say to the work of our hands: `You are our gods.'"

He must verbally confess and state these matters which he resolved in his heart.

Halacha 3

Anyone who verbalizes his confession without resolving in his heart to abandon [sin] can be compared to [a person] who immerses himself [in a mikvah] while [holding the carcass of] a lizard in his hand. His immersion will not be of avail until he casts away the carcass.

This principle is implied by the statement, [Proverbs 28:13], "He who confesses and forsakes [his sins] will be treated with mercy."

It is necessary to mention particularly one's sins as evidenced by [Moses' confession, Exodus 32:31]: "I appeal to You. The people have committed a terrible sin by making a golden idol."

Halacha 4

Among the paths of repentance is for the penitent to

a) constantly call out before God, crying and entreating;

b) to perform charity according to his potential;

c) to separate himself far from the object of his sin;

d) to change his name, as if to say "I am a different person and not the same one who sinned;"

e) to change his behavior in its entirety to the good and the path of righteousness; and f) to travel in exile from his home. Exile atones for sin because it causes a person to be submissive, humble, and meek of spirit.

Halacha 5

It is very praiseworthy for a person who repents to confess in public and to make his sins known to others, revealing the transgressions he committed against his colleagues.

He should tell them: "Though I sinned against so and so, committing the following misdeeds.... Behold, I repent and express my regret." Anyone who, out of pride, conceals his sins and does not reveal them will not achieve complete repentance as [Proverbs 28:13] states: "He who conceals his sins will not succeed."

When does the above apply? In regard to sins between man and man. However, in regard to sins between man and God, it is not necessary to publicize one's [transgressions]. Indeed, revealing them is arrogant. Rather, a person should repent before God, blessed be He, and specifically mention his sins before Him. In public, he should make a general confession. It is to his benefit not to reveal his sins as [Psalms 32:1] states: "Happy is he whose transgression is forgiven, whose sin is covered."

Halacha 6

Even though repentance and calling out [to God] are desirable at all times, during the ten days between Rosh HaShanah and Yom Kippur, they are even more desirable and will be accepted immediately as [Isaiah 55:6] states: "Seek God when He is to be found."

When does the above apply? To an individual. However, in regard to a community, whenever they repent and cry out wholeheartedly, they are answered immediately as [Deuteronomy 4:7] states: "[What nation is so great that they have God close to them,] as God, our Lord, is whenever we call Him."

Halacha 7

Yom Kippur is the time of Teshuvah for all, both individuals and the community at large. It is the apex of forgiveness and pardon for Israel. Accordingly, everyone is obligated to repent and confess on Yom Kippur.

The mitzvah of the confession of Yom Kippur begins on the day's eve, before one eats [the final meal], lest one choke to death in the meal before confessing.

Although a person confessed before eating, he should confess again in the evening service, Yom Kippur night, and similarly, repeat the confession in the morning, Musaf, afternoon, and Ne'ilah services.

At which point [in the service] should one confess? An individual confesses after the Amidah and the Chazan confesses in the midst of the Amidah, in the fourth blessing.

Halacha 8

The confessional prayer customarily recited by all Israel is: "For we have all sinned...." This is the essence of the confessional prayer.
Sins which were confessed on one Yom Kippur should be confessed on another Yom Kippur even though one remains steadfast in his repentance, as [Psalms 51:5] states: "I acknowledge my transgressions and my sins are always before me."

Halacha 9

Teshuvah and Yom Kippur only atone for sins between man and God; for example, a person who ate a forbidden food or engaged in forbidden sexual relations, and the like. However, sins between man and man; for example, someone who injures a colleague, curses a colleague, steals from him, or the like will never be forgiven until he gives his colleague what he owes him and appeases him.

[It must be emphasized that] even if a person restores the money that he owes [the person he wronged], he must appease him and ask him to forgive him.

Even if a person only upset a colleague by saying [certain] things, he must appease him and approach him [repeatedly] until he forgives him.

If his colleague does not desire to forgive him, he should bring a group of three of his friends and approach him with them and request [forgiveness]. If [the wronged party] is not appeased, he should repeat the process a second and third time. If he [still] does not want [to forgive him], he may let him alone and need not pursue [the matter further]. On the contrary, the person who refuses to grant forgiveness is the one considered as the sinner.

[The above does not apply] if [the wronged party] was one's teacher. [In that instance,] a person should continue seeking his forgiveness, even a thousand times, until he forgives him.

Halacha 10

It is forbidden for a person to be cruel and refuse to be appeased. Rather, he should be easily pacified, but hard to anger. When the person who wronged him asks for forgiveness, he should forgive him with a complete heart and a willing spirit. Even if he aggravated and wronged him severely, he should not seek revenge or bear a grudge.

This is the path of the seed of Israel and their upright spirit. In contrast, the insensitive gentiles do not act in this manner. Rather, their wrath is preserved forever. Similarly, because the Gibeonites did not forgive and refused to be appeased, [II Samuel 21:2] describes them, as follows: "The Gibeonites are not among the children of Israel."

Halacha 11

If a person wronged a colleague and the latter died before he could ask him for forgiveness, he should take ten people and say the following while they are standing before the colleague's grave: "I sinned against God, the Lord of Israel, and against this person by doing the following to him...."

If he owed him money, he should return it to his heirs. If he is unaware of the identity of his heirs, he should place [the sum] in [the hands of] the court and confess.