Tetzaveh 5632 Second Ma'amar

Yirmiyahu HaNavi compares the nation of Israel to an olive tree, "זית רענן יפה פרי תואר קרא ה' שמך .../God has called your name, 'A leafy olive tree, beautiful with shapely fruit."  Why?  The first Midrash in our parsha explains.  Among liquids oil is unique in that it floats.  Even after being mixed, it separates and floats to the top.  The nation of Israel as well will never mix with the nations of the world.  And when we do the will of God, we are on top.

The Midrash relates oil to the nation of Israel and other liquids to the nations of the world.  The Sfas Emes broadens this metaphor to include all spirituality and physicality.  Oil represents the spiritual whereas other liquids represent the physical. 

Inside each of us is a spiritual life force, a Godly portion, as it were.  Just as oil never mixes with other liquids, our job is to make sure that this spirituality remains untainted by the physical.  This is alluded to in God's instruction to Moshe to command the nation, "... ויקחו אליך שמן זית זך .../… Take for yourself pure olive oil …"  We do this by making the spiritual the crux of our lives even as we engage the physical world.