18.18 Jnanam etc.  Prompting-in-action :  the will to exert. At that time those things which - because they exist in one's thought alone - are referable by the terms knowledge, obect-of-knowledge and knowing-subject;  at the time of that will (to exert) taking the form  'I shall enjoy it; for it is caused by me'  as well as at the time of executing th act, the very same things-because they are fully absorbed  [in desire for fruits] - get the names instrument, object and agent.  Therefore, because there is no such absorption  [in desire for fruits] in the case of  the men of Yoga, there is  no  room in their action for the expressions instrument etc.; rather they exist only as knowledge etc.  This is the purport here.			
 Now  [the Lord]  speaks to explain, in brief, the classification of all these six items, basing on the classification of the Strands :-