Purport

These two Shlokas are one of the most important Shlokas on the subject of Nishkam Karma and hence liberation.
As we all know any action been performed produced either good or bad results depending upon the type of Karma. In both cases, the doer of the action is liable for the results hence produced and hence got bounded with the results of karma. This connection of doer with the results or fruits of action is what brings him into this mortal world again and again. When somebody does good karma with the desires, he has to appear in one or another type of body to enjoy the fruits of his actions. If human performs bad karma he again has to get some physical body to pay back for the liability he incurred by doing bad karma. In both cases, one has to take birth again a physical body.
Breaking this attachment of doer with his fruits is what called Moksha, the liberation from the cycle of death and birth. To achieve this state where a human is not liable or bounded with the fruits of action is the purpose of all philosophies in Sanatan Dharma. All methods of Yoga Jnana Yoga, Sankhya Yoga, Bhakti Yoga or Karma yoga achieve the same state. This very process, in other words, is what called Yoga, means to detach the soul from the cycle of birth and death and attach to the supreme soul. Yoga is the method and Moksha is the result.

Different methods of Yoga have their own advantages and disadvantages. Obviously none of those methods are easy. What define in above two Shloka is the easiest and the most effective method to achieve the state where human is free from the bounds of fruits.

Bhagvan Shri Krishna instructed Arjuna, to offer every action, every offering, and even food to Shri Krishna. In this way, you will be free from the effect of actions. The biggest advantage of the above method is that one does not need to know anything, does not need to practice anything. What he needs is the pure devotion to Bhagvan Shri Krishna and does his duty with honesty thinking he is doing his duty as an offering to Shri Krishna.
There is one danger for some people to misinterpret these shlokas, thinking even a bad action can be offered to Shri Krishna. No, its not possible, cause when one has true devotion for Shri Krishna knows that every living being represent the divine potency of Shri Krishna. Bhagvan has instructed this at so many places in Shrimad Bahgvad Gita, Such as:
“One who always sees Me everywhere and sees everything in me, I am never out of sight for
him and he never out the sight of me.”(Ch6:Sh30)
O Arjuna! A devotee of God, who regards the happiness and sorrow of others being in equality with the pleasure and pain of his own self is regarded as Supreme.
--Ch6:sh32

One who has no animosity with for any being, who is friend of everyone, who is compassionate to all., free from egoism, and maintain equanimity of mind, even in joy and sorrow, forgiving, ever satisfied, united with yoga, have a strong determination in God and have consecrated his mind and intellect to me. Such a devotee of mine is very dear to me.
--Ch12:Sh13-14

That is why it not possible for anybody to even imagine that he does something wrong and offer it to Shri Krishna. Any action thus performed with devotion to Shri Krishna and offering unto him hence automatically intended to serve the welfare of other beings. In other words, we can interpret, any action which is done for the welfare of other beings leads to liberation.