Rav Tzvi Elimelech of Lublin, the Bnei Yisoschar, writes that the Gematria of “Kisleiv,” the month during which we celebrate Chanukah, equals the Gematria of “Av HaRachamim,” the father of mercy. This seems to imply that Kisleiv and Chanukah are times when Hashem has great mercy on us and has great love for us. What is the basis for this? An additional question to ask, whose answer can perhaps shed light on our first question, is why we mention the military miracle of Chanukah in “Al HaNissim” but not the miracle of the lasting oil.
Rav Yerucham Levovitz, the Mashgiach in the Mir Yeshiva in Yerushalayim during the early 20th century, answers our second question with the following mashal: a man enters house and sees a woman cleaning a child. He doesn't know whether this lady is the mother or just a helper. He figures that if she kisses him after cleaning him, then she is definitely the mother. The baby, however, if he could, would thank the mother only for cleaning him and not for the kiss, as the kiss is merely a sign of his mother’s love. Similarly, on Chanukah, we have to thank Hashem for leading us to victory over the Greeks (similar to the mother cleaning her child) and not for the miracle of the oil (the maternal kiss). Hashem already promised that He will never let Klal Yisrael be completely destroyed (“Lo Tishachach MiPi Zar’o,” Devarim 31:21), so His saving us doesn’t signify anything. However, the Pach HaShemen, the jar of oil that lasted for 8 days, was, k’vayachol, a sign of Hashem’s love for us.
This is why we thank Hashem only for the war, but we publicize only the miracle of the oil through Hadlakas HaNeiros, which symbolizes Hashem’s love for us. This is why Pirsumei Nisa is so important with the Chanukah candles and why this mitzvah is considered so important that the Rambam considers it to be “Chavivah Me’od,” “very beloved” (Hilchot Megillah VeChanukah 4:12), because it shows Hashem's love for us and teaches that we, in turn, have to love Hashem.
From the two miracles of Chanukah, we see the tremendous rachamim and love that Hashem shows us in this time period of Chanukah. What is it that we do or did to merit this? In the time of the Chashmonaim, the Greeks (Yavan) legislated against the Torah and Mitzvot. They tried to stop Talmud Torah and Shemiras HaMitzvos in general. The Maharal of Prague explains that Yavan hated that we have the Torah and Mitzvos from Hashem. The Greeks had only “knowledge” which had no true purpose or holiness. They had purely secular wisdom and were jealous of the true Chochmah of the Torah which gives us a connection to Hashem. The Maharal further explains that Yavan’s main goal was to be metamei the Heichal, to desecrate the Beit HaMikdash, by bringing their foreign culture and ideals into the Heichal. I think it is important to note that they did not try to completely stop any Avodah in the Beit HaMikdash, but they simply wanted the Avodah to be done in unison with their empty and immoral culture. This is why it was so important that the shemen that the Chashmonaim used in the Menorah was “Shemen Zayit Zach,” completely pure oil. Even though normally we would apply the concept of “Tum’ah Hutrah B’Tzibbur,” that laws of impurity can be relaxed when nearly all of Klal Yisrael is impure themselves, and therefore not require the oil to be pure in such instances, the Chashmonaim made sure to use such oil to show that our Avodah and service of Hashem must be completely pure without the influence of foreign cultures and lifestyles. Today, unfortunately, manypeople often mix secular culture’s negative values with our eternal Torah values. Instead of recognizing the superior nature of our eternal Torah, many feel a need to fit every new and passing fad in secular culture into the Torah. We know that although the Hellenist Jews at the time of the Chanukah miracles must have thought the Chashmonaim to be too zealous and extreme, their actions were actually measures of recognition of our eternal Torah and Bris with Hashem. Hence, Hashem responded to the Chashmonaim by showing Klal Yisrael exceptional love and rachamim in that generation and for all future generations during the month of Kisleiv.