If a man says to a woman: Be betrothed to me on the condition that I am a righteous man, then even if he was a completely wicked man she is betrothed, as perhaps in the meantime he had thoughts of repentance in his mind and is now righteous...
כָּל מִצְוֹת שֶׁבַּתּוֹרָה בֵּין עֲשֵׂה בֵּין לֹא תַּעֲשֶׂה אִם עָבַר אָדָם עַל אַחַת מֵהֶן בֵּין בְּזָדוֹן בֵּין בִּשְׁגָגָה כְּשֶׁיַּעֲשֶׂה תְּשׁוּבָה וְיָשׁוּב מֵחֶטְאוֹ חַיָּב לְהִתְוַדּוֹת לִפְנֵי הָאֵל בָּרוּךְ הוּא ...זֶה וִדּוּי דְּבָרִים. וִדּוּי זֶה מִצְוַת עֲשֵׂה. כֵּיצַד מִתְוַדִּין. אוֹמֵר אָנָּא הַשֵּׁם חָטָאתִי עָוִיתִי פָּשַׁעְתִּי לְפָנֶיךָ וְעָשִׂיתִי כָּךְ וְכָךְ וַהֲרֵי נִחַמְתִּי וּבֹשְׁתִּי בְּמַעֲשַׂי וּלְעוֹלָם אֵינִי חוֹזֵר לְדָבָר זֶה. וְזֶהוּ עִקָּרוֹ שֶׁל וִדּוּי.
If a person transgresses any of the mitzvot of the Torah, whether a positive command or a negative command - whether willingly or inadvertently - when he repents, and returns from his sin, he must confess before God, blessed be He...
This refers to a verbal confession. This confession is a positive command.
How does one confess: He states: "I implore You, God, I sinned, I transgressed, I committed iniquity before You by doing the following. Behold, I regret and am embarrassed for my deeds. I promise never to repeat this act again."
These are the essential elements of the confessional prayer...
(ד) אַף עַל פִּי שֶׁתְּקִיעַת שׁוֹפָר בְּרֹאשׁ הַשָּׁנָה גְּזֵרַת הַכָּתוּב רֶמֶז יֵשׁ בּוֹ כְּלוֹמַר עוּרוּ יְשֵׁנִים מִשְּׁנַתְכֶם וְנִרְדָּמִים הָקִיצוּ מִתַּרְדֵּמַתְכֶם וְחַפְּשׂוּ בְּמַעֲשֵׂיכֶם וְחִזְרוּ בִּתְשׁוּבָה וְזִכְרוּ בּוֹרַאֲכֶם. אֵלּוּ הַשּׁוֹכְחִים אֶת הָאֱמֶת בְּהַבְלֵי הַזְּמַן וְשׁוֹגִים כָּל שְׁנָתָם בְּהֶבֶל וָרִיק אֲשֶׁר לֹא יוֹעִיל וְלֹא יַצִּיל, הַבִּיטוּ לְנַפְשׁוֹתֵיכֶם וְהֵיטִיבוּ דַּרְכֵיכֶם וּמַעַלְלֵיכֶם וְיַעֲזֹב כָּל אֶחָד מִכֶּם דַּרְכּוֹ הָרָעָה וּמַחֲשַׁבְתּוֹ אֲשֶׁר לֹא טוֹבָה...
Even though the sounding of the shofar on Rosh HaShanah is a decree, it contains an hint. It is as if [the shofar's call] is saying:
Wake up you sleepy ones from your sleep and you who slumber, arise. Inspect your deeds, repent, remember your Creator. Those who forget the truth in the vanities of time and throughout the entire year, devote their energies to vanity and emptiness which will not benefit or save: Look to your souls. Improve your ways and your deeds and let every one of you abandon his evil path and thoughts....
שנצטוינו להתודות כו'... תשובה לחוד דהיא אפילו בלב אם מתחרט בלב שלם הקב"ה מקבל תשובתו רק כאן היא מ"ע ככל מ"ע שבתורה לומר הוידוי בפה ואם לא אמר בע"פ ביטל מ"ע אבל מכל מקום לענין כפרה על העבירה שעבר נתכפר בתשובה בלב .... וכ"נ בקדושין ד' מ"ט דאם קידש ע"מ שהוא צדיק אפילו הוא רשע גמור מקודשת שמא הרהר תשובה בלבו הרי דתשובה בלב אף שלא בפה הוי צדיק ... ולא מצאתי ד"ז להדיא בגמרא דכפרה שתלוי בתשובה יהי' תלוי דוקא בוידוי פה דהיא רק מצוה נוספת כמו כל מ"ע אבל שיהא הכפרה תלוי בזה אינו מוכרח אך בר"מ כאן מבואר להדיא דהכפרה תלוי בוידוי דברים ....
ונראה דלא ק' אם נאמר דאינו מתכפר בלא וידוי דברים מהא דאמרי' בקידושין אפילו רשע גמור אמרינן שמא הרהר תשובה בלבו והוי צדיק כמו שהקשינו לעיל דבאמת צדיק ורשע אינו תלוי בכפרה כלל ... נהי דאין לו כפרה בתשובה בלב מכל מקום הוי צדיק כיון שמתחרט לפני קונו ית' ואינו תלוי בכפרה כלל ...
[This is to say] that Teshuva on its own, even if solely internally, if he does so with a full/honest heart, God receives their teshuva. And the mitzvah of viduy dvarim - verbal recitation of wrongdoing - is an [additional] mitzvah like any positive commandment in the Torah; and if the person failed to do viduy devarim, they have negated the positive commendment, but nevertheless their is a level of effective atonement for the teshuva that was done internally...
And this is what seems to be the takeaway from the gemara in Kiddushin - that if a person says, "be betrothed to me on the condition that I am a righteous man, then even if he was a completely wicked man she is betrothed, as perhaps in the meantime he had thoughts of repentance in his mind and is now righteous..."
And I have not found explicitly in the gemara anywhere that atonement which is predicated on teshuva is predicated specifically on verbal viduy - rather it is an additional mitzvah like any positive commandment - but it is not explicitly stated anywhere that viduy is a necessary part of the atonement process. However, Maimonides does state explicitly that atonement is predicated on verbal viduy...
And behold, there is not challenge to Maimonides' position from the previously cited gemara. For the truth is that the categories of "righteous" and "wicked" are not dependent on the fact of formal atonement....; even if you were to say that the internal teshuva does not work, nevertheless they are a tzaddik / righteous person, since they have deeply regretted their actions before God - and this does not depend on formal atonement...
Rav Yosef Dov Soloveitchik, Harerei Kedem, #41
...The words of the Rambam make clear that there is a specific obligation of teshuva on Rosh Hashana...which is what the shofar alludes to, as it attempts to rouse us towards teshuva.
But we must investigate this, for the nature of teshuva on Rosh Hashana is not the same as teshuva during the rest of the year - or even the same as the teshuva of Yom Kippur. For generally, the rules of teshuva are clearly laid out, and they include: verbal declaration (viduy), feelings of regret and shame, and resolving to act better moving forward. But on ROosh Hashana, we do not find discussions of this process, nor do we say viduy during the liturgy of Rosh Hashana...
Behold what we find in the gemara in Kiddushin 49b, "If a man says to a woman: Be betrothed to me on the condition that I am a righteous man, then even if he was a completely wicked man she is betrothed, as perhaps in the meantime he had thoughts of repentance in his mind and is now righteous". The Minchat Chinuch proves from this that internal repentance (teshuva) - even if not stated verbally - is considered valid teshuva and such a person can be considered righteous. He infers further that verbal repentance is not a required element of the teshuva process. It seems from his language that this is referring to a case where the person internally has regret, has a specific sin in mind, has internally committed not to repeat this action, etc., like the full order of teshuva; and has simply failed to state these things verbally.
However - in truth, it seems that the Minchat Chinuch is incorrect. For surely it is unreasonable to suggest that in one moment, a person could internally go through the processes of regret, moving away from sin, and commitment to change moving forward. Rather, it must be that when the gemara says "thoughts of repentance", it does not mean a full internal repentance; it instead means "thoughts of sin". That is to say - that one begins thinking about doing teshuva (m'harheir la'asot teshuva); the person determines in their heart that the time has arrived to do a personal and spiritual accounting, and to change their ways. And, according to the gemara, this thinking transforms a person into the category of tzaddik, righteous. And attaining the status of tzaddik does not depend on fulfilling the mitzvah of teshuva in all of its details, rather having the internal inclination to go through the teshuva process is sufficient. This seems to be the correct interpretation of this rabbinic statement.
And this is the special teshuva of Rosh Hashana, about which Maimonides states that the shofar contains a "hint": the hint is that the shofar is the "thought of repentance". For the shofar wakes one from their slumber, and from the vanities of the year, and causes them to change their path and fix their ways. This is the essence of hirhurei teshuva, beginning to think about teshuva - and the completion of teshuva is yet to come [ie on Yom Kippur]....
Franz Kafka, Parables
Leopards break into the temple and drink to the dregs what is in the sacrificial pitchers; this is repeated over and over again; finally it can be calculated in advance, and it becomes a part of the ceremony.