"and you shall be unto Me": possessed by Me and occupied with Torah and not with other things. "then you shall be unto Me a segulah" (a select treasure). Just as a man's segulah is beloved by him, so, you will be beloved by Me. R. Yehoshua b. Karcha says "to sharpen the ear": I might think (the intent is) that just as a woman "scrimps" from her husband, and a son from his father, and a servant from his master, and a maid from her mistress, so, you, "scrimp" from Me. It is, therefore, written (Ibid.) "for all the earth is Mine."