מתני׳ יום הכפורים אסור באכילה ובשתיה וברחיצה ובסיכה ובנעילת הסנדל ובתשמיש המטה והמלך והכלה ירחצו את פניהם והחיה תנעול את הסנדל דברי רבי אליעזר וחכמים אוסרין
MISHNA: On Yom Kippur, the day on which there is a mitzva by Torah law to afflict oneself, it is prohibited to engage in eating and in drinking, and in bathing, and in smearing oil on one’s body, and in wearing shoes, and in conjugal relations.
תְּנָא לֵיהּ חִיָּיא בַּר רַב מִדִּפְתִּי: כְּתִיב: ״וְעִנִּיתֶם אֶת נַפְשֹׁתֵיכֶם בְּתִשְׁעָה לַחֹדֶשׁ בָּעֶרֶב״. וְכִי בְּתִשְׁעָה מִתְעַנִּין?! וַהֲלֹא בַּעֲשָׂרָה מִתְעַנִּין! אֶלָּא לוֹמַר לְךָ כָּל הָאוֹכֵל וְשׁוֹתֶה בִּתְשִׁיעִי, מַעֲלֶה עָלָיו הַכָּתוּב כְּאִילּוּ מִתְעַנֶּה תְּשִׁיעִי וַעֲשִׂירִי.
Ḥiyya bar Rav of Difti taught him: It is written with regard to Yom Kippur: “And you shall afflict your souls on the ninth day of the month in the evening, from evening to evening you shall keep your Sabbath” (Leviticus 23:32). The Gemara wonders: And does one fast on the ninth of Tishrei? Doesn’t one fast on the tenth of Tishrei, as the Torah says at the beginning of that portion: “However, on the tenth day of this seventh month is the Day of Atonement; there shall be a holy convocation for you, and you shall afflict your souls” (Leviticus 23:27)? Rather, this verse comes to tell you: One who eats and drinks on the ninth day of Tishrei in preparation for the fast the next day, the verse ascribes him credit as if he fasted on both the ninth and the tenth of Tishrei.
How do you "use" fasting as a spiritual technology?
Why do we fast on Yom Kippur?
Is fasting itself a form of prayer?
