מַאי חֲנוּכָּה? דְּתָנוּ רַבָּנַן: בְּכ״ה בְּכִסְלֵיו יוֹמֵי דַחֲנוּכָּה תְּמָנְיָא אִינּוּן דְּלָא לְמִסְפַּד בְּהוֹן וּדְלָא לְהִתְעַנּוֹת בְּהוֹן. שֶׁכְּשֶׁנִּכְנְסוּ יְוָוֽנִים לַהֵיכָל טִמְּאוּ כׇּל הַשְּׁמָנִים שֶׁבַּהֵיכָל. וּכְשֶׁגָּבְרָה מַלְכוּת בֵּית חַשְׁמוֹנַאי וְנִצְּחוּם, בָּדְקוּ וְלֹא מָצְאוּ אֶלָּא פַּךְ אֶחָד שֶׁל שֶׁמֶן שֶׁהָיָה מוּנָּח בְּחוֹתָמוֹ שֶׁל כֹּהֵן גָּדוֹל, וְלֹא הָיָה בּוֹ אֶלָּא לְהַדְלִיק יוֹם אֶחָד. נַעֲשָׂה בּוֹ נֵס וְהִדְלִיקוּ מִמֶּנּוּ שְׁמוֹנָה יָמִים. לְשָׁנָה אַחֶרֶת קְבָעוּם וַעֲשָׂאוּם יָמִים טוֹבִים בְּהַלֵּל וְהוֹדָאָה.
Gemara asks: What is Hanukkah, and why are lights kindled on Hanukkah? The Gemara answers: The Sages taught in Megillat Ta’anit: On the twenty-fifth of Kislev, the days of Hanukkah are eight. One may not eulogize on them and one may not fast on them. What is the reason? When the Greeks entered the Sanctuary they defiled all the oils that were in the Sanctuary by touching them. And when the Hasmonean monarchy overcame them and emerged victorious over them, they searched and found only one cruse of oil that was placed with the seal of the High Priest, undisturbed by the Greeks. And there was sufficient oil there to light the candelabrum for only one day. A miracle occurred and they lit the candelabrum from it eight days. The next year the Sages instituted those days and made them holidays with recitation of hallel and special thanksgiving in prayer and blessings.