Nimittamatram Bhav Savyachin – Arjuna could send arrows even by left hand with same efficiency as that of right hand. It shows his prowess. Mananeeya Eknathji also must have meant the similar thing while addressing it to the karyakartas. We should use our both hands to do the work that is in front of us. With all might the work is to be taken up and no effort should be left undone.
'Therefore,' the Lord says, 'may you be purely an instrument.' All that the Arjuna has to do is to send some arrows. That is his part in the scheme of things. He is presented here with something, which he did not ask for and in fact did not want. So, it is very clear that it is his prarabhda. There is a scheme behind all this. 'Therefore,' Krishna says, 'do not bring your will into this and disturb the whole thing. Because, here, any decision based on your will would be adharma. Your will must conform to 'what is to be done.' And here, 'what is to be done' is very obvious. Therefore, get up and be a mere instrument in the ensuing battle.' Everything is waiting for you. All you have to do is to send some of those arrows of yours. The enemies will all fall like pack of cards.
Eknathji is similarly telling all of us to give all that is in your capacity to do the work that has come to your lot. It must be one's prarabdha. It is only to be done as God has ordained it for us. As niyatam karma, it is to be done. As an instrument – tav eva karyartham- bhava is to be strengthened and work is to be done. It is the glory to have this bhava and do God's work.