The discussion of the mitzvah of confession and repentance explains the role of verbal acknowledgment before God and the spiritual purpose of articulating one's wrongdoing.
מִצְוַת וִדּוּי עַל הַחֵטְא – שֶׁנִּצְטַוִּינוּ לְהִתְוַדּוֹת לִפְנֵי הַשֵּׁם עַל כָּל הַחֲטָאִים שֶׁחָטָאנוּ בְּעֵת שֶׁנִּתְנַחֵם עֲלֵיהֶן, וְזֶהוּ עִנְיַן הַוִּדּוּי שֶׁיֹּאמַר הָאָדָם בְּעֵת הַתְּשׁוּבָה אָנָּא הַשֵּׁם חָטָאתִי, עָוִיתִי וּפָשַׁעְתִּי כָּךְ וְכָךְ. כְּלוֹמַר שֶׁיַּזְכִּיר הַחֵטְא שֶׁעָשָׂה בְּפֵרוּשׁ בְּפִיו. וִיבַקֵּשׁ כַּפָּרָה עָלָיו וְיַאֲרִיךְ בַּדָּבָר כְּפִי מַה שֶׁיִּהְיֶה צַחוּת לְשׁוֹנוֹ. וְאָמְרוּ זִכְרוֹנָם לִבְרָכָה, שֶׁאֲפִלּוּ הַחֲטָאִים שֶׁחִיְּבָה הַתּוֹרָה קָרְבָּן עֲלֵיהֶם, צָרִיךְ הָאָדָם אֶל הַוִּדּוּי עִם הַקָּרְבָּן, וְעַל זֶה נֶאֱמַר (במדבר ה ו) דַּבֵּר אֶל בְּנֵי יִשְׂרָאֵל אִישׁ אוֹ אִשָּׁה כִּי יַעֲשׂוּ מִכָּל חַטֹּאת הָאָדָם לִמְעֹל מַעַל בַּיי וְאָשְׁמָה הַנֶּפֶשׁ הַהִיא וְהִתְוַדּוּ אֶת חַטָּאתָם אֲשֶׁר עָשׂוּ. וְאָמְרוּ בַּמְּכִילְתָּא (ספרי זוטא כאן) לְפִי שֶׁנֶּאֱמַר (ויקרא ה ה) וְהִתְוַדָּה אֲשֶׁר חָטָא, יִתְוַדֶּה עַל חֵטְא שֶׁחָטָא עָלֶיהָ, עַל חַטָּאת כְּשֶׁהִיא קַיֶּמֶת, לֹא מִשֶּׁנִּשְׁחֲטָה, כְּלוֹמַר בְּעוֹד שֶׁבֶּהֱמַת הַקָּרְבָּן חַיָּה, וְלֹא מִשֶּׁנִּשְׁחֲטָה. וְעוֹד אָמְרוּ שָׁם לָמַדְנוּ חִיּוּב הַוִּדּוּי לִמְטַמֵּא מִקְדָּשׁ וְקָדָשָׁיו, מִנַּיִן אַתָּה מַרְבֶּה שְׁאָר כָּל הַמִּצְוֹת, כְּלוֹמַר שֶׁהַמִּקְרָא הַזֶּה בָּא בְּפָרָשַׁת וַיִּקְרָא בִּמְטַמֵּא מִקְדָּשׁ וְקָדָשָׁיו, מִנַּיִן אַתָּה מְרַבֶּה שְׁאָר כָּל הַמִּצְוֹת? דִּכְתִיב דַּבֵּר אֶל בְּנֵי יִשְׂרָאֵל וְגוֹ' וְהִתְוַדּוּ. כְּלוֹמַר, שֶׁנִּדְרָשׁ הַכָּתוּב כְּאִלּוּ לֹא נִכְתַּב עַל דָּבָר מְיֻחָד. וּמִנַּיִן שֶׁיֵּשׁ בַּמַּשְׁמָע הַזֶּה אַף מִיתוֹת וְכָרֵתוֹת? שֶׁנֶּאֱמַר גַּבֵּי וִדּוּי אַהֲרֹן בְּאַחֲרֵי מוֹת (שם טז טז) לְכָל חַטֹּאתָם. וְדָרְשׁוּ זִכְרוֹנָם לִבְרָכָה לְרַבּוֹת מִצְוֹת לֹא תַעֲשֶׂה, וְכִי יַעֲשׂוּ דִּכְתִיב כָּאן לְרַבּוֹת מִצְוֹת עֲשֵׂה, כְּלוֹמַר, אִם בִּטֵּל מִצְוַת עֲשֵׂה שֶׁהָיָה יָכוֹל לַעֲשׂוֹת שֶׁחַיָּב לְהִתְוַדּוֹת עָלֶיהָ. וְעוֹד דָּרְשׁוּ שָׁם בַּמְּכִילְתָּא מִכָּל חַטֹּאת הָאָדָם, מִמָּה שֶׁבֵּינוֹ לְבֵין חֲבֵרוֹ עַל הַגְּנֵבוֹת וְעַל הַגְּזֵלוֹת וְעַל לָשׁוֹן הָרַע, וְזֶה הַוִּדּוּי, צָרִיךְ בֶּאֱמֶת שֶׁיָּשִׁיב הֶחָמָס אֲשֶׁר בְּכַפָּיו, שֶׁאִם לֹא כֵּן מוּטָב שֶׁלֹּא יִתְוַדֶּה עַל זֶה. לִמְעֹל מַעַל לְרַבּוֹת כָּל חַיָּבֵי מִיתוֹת שֶׁיִּתְוַדּוּ. יָכוֹל אַף הַנֶּהֱרָגִין עַל פִּי זוֹמְמִין, כְּלוֹמַר אַף עַל פִּי שֶׁהוּא יוֹדֵעַ שֶׁלֹּא חָטָא, אֶלָּא שֶׁהוּעַד עָלָיו עֵדוּת שֶׁקֶר, שֶׁיְּהֵא חַיָּב לְהִתְוַדּוֹת עַל זֶה? תַּלְמוּד לוֹמַר וְאָשְׁמָה הַנֶּפֶשׁ, לֹא אָמַרְתִּי אֶלָּא כְּשֶׁיִּהְיֶה שָׁם אַשְׁמָה, אֲבָל לֹא כְּשֶׁיֵּדַע שֶׁאֵין לוֹ חֵטְא אֶלָּא שֶׁהוּעַד שֶׁקֶר עָלָיו. הִנֵּה הִתְבָּאֵר שֶׁכָּל הָעֲוֹנוֹת הַגְּדוֹלִים וְהַקְּטַנִּים וַאֲפִלּוּ מִצְוֹת עֲשֵׂה חַיָּב הָאָדָם עֲלֵיהֶם הַוִּדּוּי. וּלְפִי שֶׁבָּאָה מִצְוָה זוֹ שֶׁל וִדּוּי עִם חִיּוּב הַקָּרְבָּן, כְּמוֹ שֶׁכָּתוּב בְּפָרָשַׁת וַיִּקְרָא דִּכְתִיב שָׁם (ה ו) וְהֵבִיא אֶת אֲשָׁמוֹ וְגוֹ, שֶׁמָּא יַעֲלֶה בְּמַחֲשָׁבָה שֶׁאֵין הַוִּדּוּי לְבַדּוֹ מִצְוָה בִּפְנֵי עַצְמָהּ, אֶלָּא מֵהַדְּבָרִים הַנִּגְרָרִים אַחַר הַקָּרְבָּן, עַל כֵּן הָיוּ צְרִיכִים לְבָאֵר בַּמְּכִילְתָּא שֶׁאֵינוֹ כֵּן, אֶלָּא מִצְוָה בִּפְנֵי עַצְמָהּ הִיא. וְכֵן אָמְרוּ שָׁם יָכוֹל בִּזְמַן שֶׁהֵם מְבִיאִין מִתְוַדִּין, וּמִנַּיִן אַף בִּזְמַן שֶׁאֵין מְבִיאִין, שֶׁנֶּאֱמַר בְּנֵי יִשְׂרָאֵל וְהִתְוַדּוּ. כְּלוֹמַר שֶׁהַקַּבָּלָה בָּאָה לִדְרֹשׁ כֵּן. וַעֲדַיִן הָיִיתִי אוֹמֵר, שֶׁאֵין הַוִּדּוּי אֶלָּא בָּאָרֶץ, כְּלוֹמַר אַף עַל פִּי שֶׁמִּתְוַדִּין בְּלֹא קָרְבָּן, מִכָּל מָקוֹם שֶׁלֹּא יִהְיֶה חִיּוּב הַוִּדּוּי אֶלָּא בָּאָרֶץ, כִּי שָׁם עִקַּר הַכַּפָּרָה, וְשָׁם הַקָּרְבָּנוֹת, וְעִקַּר הַכֹּל בָּהּ. מִנַּיִן אַף בַּגָּלוּיוֹת? דִּכְתִיב (שם כו מ) וְהִתְוַדּוּ אֶת עֲוֹנָם וְאֶת עֲוֹן אֲבֹתָם. כְּלוֹמַר עֲוֹן אֲבוֹתָם שֶׁחָטְאוּ וְגֹרְשׁוּ מִן הָאָרֶץ. וְכֵן אָמַר דָּנִיֵּאל בְּחוּצָה לָאָרֶץ (ט ז) לְךָ יְיָ הַצְּדָקָה וְלָנוּ בֹּשֶׁת הַפָּנִים כַּיּוֹם הַזֶּה. הִנֵּה הִתְבָּאֵר שֶׁהַוִּדּוּי מִצְוָה בִּפְנֵי עַצְמָהּ, וְנוֹהֵג בְּכָל מָקוֹם. וְאָמְרוּ גַּם כֵּן בַּסִּפְרָא (אחרי ד ו) וְהִתְוַדָּה זֶה וִדּוּי דְּבָרִים. מִשָּׁרְשֵׁי הַמִּצְוָה. לְפִי שֶׁבְּהוֹדָאַת הֶעָוֹן בַּפֶּה תִּתְגַּלֶּה מַחְשֶׁבֶת הַחוֹטֵא וְדַעְתּוֹ, שֶׁהוּא מַאֲמִין בֶּאֱמֶת, כִּי גָּלוּי וְיָדוּעַ לִפְנֵי הָאֵל בָּרוּךְ הוּא כָּל מַעֲשֵׂהוּ, וְלֹא יַעֲשֶׂה עַיִן רוֹאָה כְּאֵינָהּ רוֹאָה, גַּם מִתּוֹךְ הַזְכָּרַת הַחֵטְא בִּפְרָט וּבְהִתְנַחֲמוֹ עָלָיו יִזָּהֵר מִמֶּנּוּ יוֹתֵר פַּעַם אַחֶרֶת לְבַל יְהִי נִכְשָׁל בּוֹ, אַחַר שֶׁיֹּאמַר בְּפִיו כָּזוֹ וְכָזוֹ עָשִׂיתִי וְנִסְכַּלְתִּי בְּמַעֲשַׂי, יִהְיֶה נִגְדָּר שֶׁלֹּא יָשׁוּב לַעֲשׂוֹת כֵּן, וּמִתּוֹךְ כָּךְ יֵרָצֶה לִפְנֵי בּוֹרְאוֹ בָּרוּךְ הוּא. וְהָאֵל הַטּוֹב הֶחָפֵץ בְּטוֹבַת בְּרִיּוֹתָיו הִדְרִיכָם בְּדֶרֶךְ זוֹ יִזְכּוּ בָּהּ.
The commandment of confession of sin: We are commanded to confess before God our sins that we have sinned, at such time that we feel remorse for them. And this is the content of confession: to say at the time of repentance, “Please, God, I have sinned, I have transgressed, I have rebelled [in] such and such,” meaning to say that he mention the sin that he did explicitly with his mouth. He should [then] seek atonement for it and extend his words in this matter according to his fluency. And they, may their memory be blessed, said that even sins that require the bringing of a sin-offering still demand confession with the offering, and about this it states (Numbers 5:6), “Speak to the children of Israel [saying], a man or woman who commits from any of the sins of man and rebels against the Lord, that soul is guilty and they shall confess the sins that they did.” [The Sages] said in the Mekhilta (Sifrei Zuta on Numbers 5:6), “Since it says ‘confess the sin’ (Leviticus 5:5) it means that the sin must be extant, that is that the sin-offering is alive and not slaughtered.” This means that the animal to be offered must still be alive. They also said there, “We see that one must confess if he renders impure the Temple and its holy things. From where do you know to include all other commandments?” That is that this verse in Parashat Vayikra only [discusses] one who renders impure the Temple and its holy things; from where do you know to include all other commandments? “As it is written, ‘Speak to the children of Israel, etc. and they should confess.’” That is, that we expound the verse as if it is not written about a specific thing. “And from where do we know that its understanding [includes sins that are punishable by] death and excision? Since it is stated about the confession of Aharon in Acharei Mot (Leviticus 16:16) ‘for all their sins.’” [The Sages], may their memory be blessed, expounded [on this verse] to include negative commandments; and “that they did” which is written here to include positive commandments, meaning to say that if he does not do a positive commandment that he could have done, he is obligated to confess about it. And they further expounded there in the Mekhilta, “‘From any of the sins of man’ — from that which is between him and his fellow: theft, robbery and evil speech.” And this confession truthfully requires that he return the “[theft] that is in his hands,” as if he does not do so it would be better not to confess about it. “‘To rebel’ includes all those sentenced to death who must [also] confess. I might have thought to include even those convicted by false witnesses”; that is, even though he knows that he did not sin, except that false testimony was testified against him, that he be obligated to confess about this. “Hence the verse teaches, ‘soul [that] is guilty’ — I only said when there is guilt there, but not when he knows that he did not sin, except false testimony was testified against him. Hence we understand that [for] all iniquities, large and small — even positive commandments — a man is obligated to confess about them. And since this commandment of confession comes with the obligation to bring an offering — as is written in Parashat Vayikra there (Leviticus 5:6), “And he shall bring his guilt-offering, etc.” — one might think that the confession is not an independent commandment on its own, but rather only one of the things that are an extension of the sacrifice. Therefore they had to elucidate in the Mekhilta that such is not the case, but rather it is indeed an independent commandment. And so they said there, “I might have thought that I only confess when they brought [offerings]. From where do I know even at the time that they do not bring [them]? Since it is stated, ‘the children of Israel[...] and they shall confess’” — meaning to say that the tradition comes to expound [it] in this way. “Still, I might have thought that there is confession only in the Land”; that is, even though one may confess without the sacrifice, nonetheless, that the obligation for confession is only in the Land, as that is the locus of atonement, and the sacrifices are there and the locus of everything is there. “From where do I know to include the Diaspora? From that which is written (Leviticus 26:40), ‘And they shall confess their iniquity and the iniquity of their fathers.’” That is, the iniquity of their fathers who sinned and were exiled from the Land. “And so [too,] did Daniel say outside of the Land (Daniel 9:7) ‘For You, Lord, is the righteousness and for us is the shame on this day.’” Hence it is elucidated that confession is an independent commandment and that it is practiced in all places. And they also said in the Sifra (Sifra, Acharei Mot, Section 4:6), “‘And they shall confess’ — that is verbal confession.” It is from the roots of this commandment [that it is] because through the verbal admission of iniquity, the sinner reveals his thoughts and opinion: that he truly believes that all his deeds are revealed and known before God, blessed be He, and that he will not act as if ‘the Eye that sees’ does not see. Furthermore, through mentioning the sin specifically, and through his remorse about it, he will be more careful about it on another occasion not to stumble in the same way again. Since he declares verbally, “I did such-and-such, and I stumbled in my deeds,” he will have created a fence so he will not repeat what he did. And through this he will be wanted by his Creator, blessed be He. And the Good God, Who wants the good for His creations makes them walk in this way, [that] they merit with it.