Chanukah commemorates and publicizes the miracle of the oil which lasted for eight days. Oil is unique in that it is an edible substance, but it is never consumed alone. We add oil to foods, and it enhances them, but oil by itself is harmful to a person. Thus, it is demands explanation why the festival of Chanukah is celebrated with oil and not with a festive meal (consisting of bread, wine, and water) as all other festivals are (including Purim, which is similar to Chanukah in many ways).
Let us examine these substances, all of which serve as a moshol for Torah:
Bread and water are a perquisite for life — a person must have bread to eat and water to drink in order to survive. This refers to the revealed Torah, which is necessary for a Jew in order to know how to fulfill the mitzvos.
Wine is a luxury, one can subsist without it. Nonetheless, it adds enthusiasm and pleasure to the meal. This corresponds to the secrets of Torah.
Oil is also not essential, but is only consumed in very small quantities that are added to other foods. The oil refers to the “secrets of the secrets” of the Torah.
Chanukah is commemorated with oil because it is the first step in the revelation of Pnimiyus Hatorah, the inner dimension of Torah which was first “squeezed out of the olives” through the self-sacrifice of the Maccabees as they stood firm and battled the Yavanim, the Greeks (and their Jewish Hellenist supporters) who accepted only the most superficial perspective of Torah. (And in fact, the oil is commemorated through the candles, and not through eating; the Jewish custom of eating foods cooked in oil (latkes and sufganyiot) shows the inclination and desire to internalize this aspect of Torah which evolved in subsequent generations.)
Oil, the “secrets of the secrets” of Torah, became progressively more revealed: first through Rabbi Shimon bar Yochai and the Zohar; later through the teachings of the Arizal; next came the revelations of Chassidus through the Baal Shem Tov; and then Chassidus Chabad, which brings the teachings of Pnimiyus Hatorah in a way which can be consumed and internalized (and not just observed, like candles). This progressive development in the revelation of the inner dimension of Torah is associated with Moshiach, for the term Moshiach itself means “anointed” (with oil).
Oil can be burned to provide light which illuminates the darkness. As the darkness of exile increases, there is a greater need for a greater amount of oil (meaning an increase in the learning of Pnimiyus Hatorah). In these last moments of exile, when the darkness is greatest, there is a greater need than ever for oil, to the point where the Rebbe says that oil is in fact a necessity in our times. In fact, as far as fighting darkness goes, Pnimiyus Hatorah is more necessary than the revealed Torah.
The revelation of the “oil” of Torah at Chanukah and (even more so on) Yud Tes Kislev is (not only due to the need that is generated by the increasing darkness of the world, but rather) also and primarily due to the fact that we are proceeding and coming closer to the coming of Moshiach Tzidkeinu, who is called “Moshiach” because he is “anointed” with oil…and through him comes the main and complete revelation of the oil (secrets of the secrets) of Torah…for the main study in the days of Moshiach will be in the secrets of the secrets of Torah. (As stated in Igeres Hakodesh 26: “They will know all the fundamentals of the revealed plane of the Torah from Pnimiyus Hatorah“.)
Not only is the implication that the “oil” of Torah is coming as an antidote to the increasing darkness, but the Rebbe notes that:
Our approach to the coming of Moshiach Tzidkeinu is also the reason for the strengthening of the darkness in the world — because it is due to the strengthening of holiness that there comes about a strengthening of the opposing side, which opposes the coming of Moshiach Tzidkeinu, and there is a need to fight with the opponent, and this is the idea that “he [Moshiach] fights the wars of Hashem” until “he is victorious”.
The wars of Moshiach are fought by “the soldiers of the house of Dovid“, which in recent generations was the intent of the foundation of Yeshivas Tomchei Temimim by the Rebbe Rashab. They go out to war against “those who scoff at the footsteps of your anointed one” and are victorious, bringing about the revelation of Dovid, Malka Meshicha. “And especially in our generation, when all the matters have already been completed, and we need only to ‘open up the eyes’ and to see that ‘behold, this one (Melech Hamoshiach) comes’.”
The Rebbe also touches on the distinction between “ketz haYamim” and “ketz haYamin” (see Tazria-Metzora) the “end” of days (of exile) and the “end” (meaning the beginning) of the “right side” (of the Geuloh). These correspond with the two reasons for the dissemination of the “oil” of Torah stated above: the strengthening of the darkness and the approach of the coming of Moshiach (and also with this week’s parsha, Mikeitz). This issue of the “ketz” takes us out of exile and into Geuloh, which is the subject of the sequence of the Torah portions from last week, Vayeishev, through the next three weeks into Vayechi:
…[these parshas] are connected with the subject of the Geuloh: “Vayeshev Yaakov”, that Yaakov sought to settle in tranquility — the ultimate tranquility of the Messianic Era, since from his side he was already prepared for the Geuloh. [Footnote 96: As emphasized in parshas Vayishlach — that Yaakov sent messengers to Esav his brother to inform him that the birurim were already finished and the time has arrived that they go together towards the Geuloh…to such a degree that even after the messengers informed him that Esav was not yet refined at all, nonetheless he did not involve himself in “avodas habirurim” but rather he sent an offering, “halaas ma’n to elicit ma’d of the makif of Tohu“, in order that he would have the ultimate state of the time-to-come when the transcendent level of Tohu will be drawn down and will be revealed b’pnimiyus in Tikkun.]
From this we proceed to parshas Vayechi, which refers to the “eternal life of Yaakov Avinu in the world of the resurrection.” (And this includes every Jew, for they are named “Yisroel” after him.)
Even while Yaakov Avinu was in Egypt, and these are referred to as his best years, nonetheless he and his children were not satisfied with this, not satisfied with being that Pharaoh gave them the best land of Egypt, because the main thing by them was the Geuloh. Thus, “even dwelling in Egypt for a period of time is only for the purpose of bringing the ultimate Geuloh, since through the refinement of Egypt the Geuloh will be in a loftier manner, in the ultimate perfection [in a way which includes the perfection of the intellect].”
The Rebbe concludes that we must strengthen our belief and our anticipation of the coming of Moshiach, to such a degree that he feels that as long as Moshiach Tzidkeinu still didn’t arrive in actuality and in a revealed way, one’s “days” are lacking. And the main thing: to add in the study and dissemination of Pnimiyus Hatorah, the oil of Torah, in a way where it illuminates the outside (like Chanukah candles), until it brings about the end of “legs of the rebellious ones”. In this way we can reach the time when “all the fasts will in the future be nullified to* the Days of Moshiach” (Rambam) and not only that, but they will become festival days and days of rejoicing.
* Interesting to note the exact language of the Rambam: that the fast days will be “nullified to” the days of Moshiach (לבטל לימות המשיח, rather than “nullified in”), perhaps implying that they will not be cancelled, but rather the great Divine revelations of the Messianic Era, especially the second stage which brings to Techiyas Hameisim when there is no eating or drinking, will nullify them even without there being any change in them. This is close to the explanation of Chassidus on the words of the Sages that in the future to come the Festivals will be nullified — not cancelled (G-d-forbid, for they are part of Torah), but rather the Divine revelation which occurs on the festivals will be nullified to the greater revelations of Moshiach, to the point that they will be rendered inconsequential (without being cancelled, like a candle which is overwhelmed by a bonfire).