18.18 Jnanam, knowledge (-being derived in the sense of 'that through which something is known', jnana means knowledge concerning all things in general-): so also jneyam, the object of knowledge (-that also is a reference to all objects in general-); similarly, parijnata, the knower, the experiencer, a product of ignorance, who partakes of the nature of the limiting adjuncts;-thus, this tripartite group formed by these is the trividha, threefold; karma-codana, inducement ot action, inducer of all actions in general. For, it is when the three, viz knowledge etc., combine that commencement of all actions meant either for acceptance or rejection [Acceptance, rejection or indifference.] are possible. After that, what are initiated by the five, viz locus etc., and are grouped in three ways according to the differences of their being based on speech, mind and body become comprehended under the three, viz instrument etc. This is what is being stated: Karma-sangrahah, the comprehension [It is well know that actions are based on the three-instrument etc.] of actions; iti, comes under; trividhah, three heads, three classes; viz karanam, the instrument (-derived in the sense of that through which anything is done-), i.e. the external (organs) (ear etc.) and the internal (organs) (intellect etc.); karma, the object (-derivatively meaning that which is most cherished by the subject and is achieved through an act-); and karta, the subject (agent), who employs the instrument etc., who partakes of the nature of the limiting adjuncts.
Sangrahah is derived thus: that in which something is comprehended. The comprehension of action (karma) is karma-sangrahah. Indeed, action becomes included in these three. Hence is this 'threefold comprehension of action'.
Now then, since action, instrument and result are all constituted by the gunas, it becomes necessary to state the three fold variety in them based on the differences among the gunas, viz sattva, rajas and tamas. Hence it is begun: