Srimad Bhagavadgita Sadhaka Sanjivani -Swami Ramsukhdas
In the worship of the attributeless Absolute, the main obstacle, is that a devotee identifies himself, with the body. So the term 'Dehavadbhih' has been used. In order to, remove this identification, the Lord has given his guidance in the thirteenth and the fourteenth chapters, though Arjuna did not put the question. The Lord, clearly explains, that a body (field), is different, from the soul (knower of the field) in the first verse of the thirteenth chapter, in order to remove the identification with body.