Being On Fire in Avodas Hashem Puts the Yetzer Hara Totally Out of The Way

Yaakov shmeared the stone with oil. The Meforshim say that this was a forerunner of the Mizbeach and the Kelim (vessels) of Bais Hamikdash which needed to be shmeared with oil. Oil is the source of fire, and on the Mizbeach there was a Mitzva of: אֵשׁ תָּמִיד תּוּקַד עַל הַמִּזְבֵּחַ לֹא תִכְבֶּה (צו ו) preserving a constant fire. This could be a Remez to Yaakov Avinu, who was entering the Treife world of Lavan. Tricky Lavan symbolizes the "tricky" Yetzer Hara, which tricks us by making it seem like a Mitzva when it's really an Aveira. And just like the: וְהַנָּחָשׁ הָיָה עָרוּם (בראשית ג א) sneaky "snake" was "cunning", Chazal teach us to be: עָרוּם בְּיִרְאָה (ברכות יז א) shrewd and cunning in Yiras Shamayim!

The oil symbolizes fire, to teach us that a Yid needs always to be on fire in Avodas Hashem (like R' Ahron Kotler Zatzal, whose Yahrtzeit was this Tuesday, 2 Kislev) which puts the Yetzer Hara out of the way entirely. Although oil is itself not fire, only potential fire, yet if a Yid shows a connection even with "potential" fire, it will also give him much Siyata Dishmaya.

Yaakov is the symbol of Milchemes HaYetzer, since he had the Yetzer Hara with him in the same belly (Eisav), and he had to literally fight with the Malach of Eisav. The true way to conquer the Yetzer Hara is with the fire of Torah, or Mussar B'hispa'alus (or both). For good reason Yaakov was the Torah-part of the Avos, and he learned 14 years before going to Lavan. Lots of Torah is the best preparation for the Yetzer Hara!