On his way to Charan, after fourteen years of seclusion and study in the house of Eber, Jacob “took the stone … set it as a monument, and poured oil on its head.”
Monuments are built of stone. For a more monumental monument, one takes bigger and more substantial stones. What is the oil all about?
But in order for the monument to be “a house of G-d” (as Jacob proclaimed, “And this stone which I have set as a monument shall be the house of G-d”), one requires “oil.” Oil is extracted from the olive only when it is trod upon and crushed. “Oil” thus represents a person’s self-abnegation and submission to G-d.
To walk away from Eber’s house, to walk away from fourteen years of in-depth Torah study to begin dealing with the material world—as Jacob did with his move to Charan—requires a great deal of “oil.” Only one who has totally abnegated his own will to that of G-d is capable of such sacrifice.
From an address by the Rebbe, Kislev 23, 5711 (December 2, 1950).
Adapted from the writings of the Rebbe by Yanki Tauber.
 Genesis 28:18
 Ibid., v. 22
 Hitvaaduyot 5711, vol. 1, pp.147-148