Parshat Ekev includes the fourth and last of the Parshiot of Tefillin. In the context of the mitzvah of Tefillin one puts all four Parshiot both on the arm and on the head. Throughout our Parsha series we have described the two basic impulses of life as Doing and Being. The two components of Tefillin reflect these two impulses, that of the arm represents the need to sanctify the doing, whereas that of the head, the need to sanctify the being, one's essential consciousness. The terminology used by the Torah bears out this idea. Relating to the Tefillin of hand, the Torah uses an active verb וקשרתם,"you will tie". For the Tefillin of the head the word used isוהיו , "and it will be". The Tefillin of the hand challenges us to ask the question "what to do?", that of the head, "who am I?"