חנוכה - Hanukkah
The days of Hanukkah are auspicious to repair all the days that have passed through a person's life, as the holy writings explain the verse "With 'this' will the iniquity of Jacob be atoned" (Isaiah 27:9), which is a reference to "Zos Chanukah" (literally "This" Hanukkah - the last day of Hanukkah), which is a time of repentance and atonement. It is possible to accomplish during these days what is not possible to accomplish with the power of any other Sabbaths or Festivals, not even the High Holy Days. Therefore, every person should see to it to strenghten his efforts, with love of God, during these days to have more Torah and to repent and do good deeds. Our Rebbe warned us not to waste time during these days with nonsense and vanities, and he would teach in the name of the Tzaddikim that it says in the Talmud, "What is Hanukkah? The Rabbis teach..." (Talmud: Tractate Shabbos 21b), that the holiness of Hanukkah is "The Rabbis teach", that during this time we should increase our Torah study, and he would tell anyone who would come in to meet him during Hanukkah that they should study the discussions in the Talmud tractate Shabbos (pages 21a-23b) concerning Hanukkah.
(Sefer Orchos Dovid - the Teachings of Grand Rabbi David Mattisyahu Rabinowitz, the previous Biala Rebbe - p. 53)