"The Alter Rebbe, Rabbi Schneur Zalman of Liadi, devotes a great deal of commentary to the fact that oil as a vehicle of fire has enormous advantages over grain and wine, in that it can transmit without losing its substance.
The more I share my grain and wine, the less I have.
In contrast, a flame that can be used to light a thousand other flames, and a soul can kindle a thousand others."
From The Seven Lights by Rabbi Adin Steinsaltz, p. 348