Rav Elchonon Wasserman once asked why the torah is referred to as ‘Toshiya – Counsel”?
He answered by explaining that all wisom and counsel comes from the Torah itself. The fact is that we rely on our leaders and sages to give us their counsel based upon their deep knowledge and understanding of the Torah Hakedosha. This is the meaning of “Da’as Torah”.
<From Rav Simcha Wasserman>