chetasaa sarvakarmaani mayi sanyasya matparaha |
buddhiyogaamupaashritya macchitaha satatam bhava || 57 ||

Mentally surrender all actions to me, designate me as the supreme goal, fix your mind on me by depending upon the yoga of intellect.
chetasaa : mentally
sarvakarmaani : all actions
mayi : to me
sanyasya : surrender
matparaha : me as supreme goal
buddhiyogam : yoga of intellect
upaashritya : depending upon
macchitaha : mind fixed on me
satatam : always
bhava : make
Shri Krishna summarizes karma yoga and bhakti yoga in this shloka. As we saw in the previous shloka, we need to continue performing our duty, and not to worry too much if we inadvertently perform a prohibited action, and to consider Ishvara as the one and only one aashraya, the ultimate refuge. How does this actually work in practice? A step by step approach towards karma yoga and bhakti yoga is enumerated in this shloka for the convenience of the seeker.
First, the seeker should fix Ishvara as his ultimate goal. This is mat paraha, one who is completely oriented towards Ishvara. Next, such a seeker should surrender all his actions to Ishvara. In the ninth chapter, Shri Krishna had said – whatever you do, whatever you consume, whatever you offer or donate, and whatever penance you perform, submit it to me. This is sarvakarmaani sanyasya. Nothing is done for selfish ends such as wealth, power, position, vanity and so on. All is done for Ishvara only.
Now, when the seeker faces challenges in life, he needs to have a method to deal with them. Equanimity is the answer. All actions are performed with full awareness and knowledge, as an offering to Ishvara. No action is perform haphazardly. Once the action is complete, the seeker should neither be attached to success, nor to failure. Such an attitude will only develop as a result of accepting every object, person or situation encountered in life as a gift or a praasada from Ishvara. This is buddhi yoga, as described in the second chapter.