There are sins which are still in the form of a seed, and there are others which are already fructified and are giving us fruit, which we are enjoying as distress and pain.ДЄs explained in the twenty-eighth verse of the Seventh Chapter, a person who has completely ended the reactions of all sinful activities and who is fully engaged in pious activities, being freed from the duality of this material world, becomes engaged in devotional service to the Supreme Personality of Godhead, Krishna.

The sinful action may have already stopped within the individual, but the results or the fruit of that sinful action are still to be enjoyed. Similarly, a man performs a sinful act, and like a seed it takes time to fructify. It is first a small, sprouting plant, then it assumes the form of a tree, then it flowers and bears fruit, and, when it is complete, the flowers and fruits are enjoyed by persons who have sown the seed of the tree. For instance, when the seed of a particular tree is sown, the tree does not appear immediately to grow it takes some time. Those who are engaged in fruitive activities are entangled in different stages and forms of sinful reactions. In the Padma Purana, manвЂ™s sinful activities have been analyzed and are shown to be the results of sin after sin. This knowledge is the purest form of all activities, as explained in Vedic literature. These activities of the spirit soul are therefore indicated here as constituting the king of all knowledge, the most confidential part of all knowledge. If it is eternal, then it is eternally active, and its activities in the spiritual kingdom are the most confidential part of spiritual knowledge. How can the soul, which is so active within this body, be inactive after being liberated from the body? It is always active. Sometimes people are under the impression that the soul is different from the body and that when the body is finished, or one is liberated from the body, the soul remains in a void and becomes impersonal. But that gives no positive information about the soul. That is a confidential part of knowledge: simply knowing that the spirit soul is different from this body and that its nature is immutable, indestructible and eternal. In the very beginning, the Lord says that this body is perishable and that the soul is not perishable (antavanta ime deha nityasyoktah saririnah). The Bhagavad-gita, especially from the Second Chapter on, stresses the importance of the soul. Still people are placing great stress on the bodily necessities of life, not caring for the vital soul. Yet the soul is the most important part of the body without the presence of the soul, the body has no value. There are so many departments of knowledge all over the world and many huge universities, but there is, unfortunately, no university or educational institution where the science of the spirit soul is instructed. As far as ordinary education is concerned, people are involved with so many departments: politics, sociology, physics, chemistry, mathematics, astronomy, engineering, etc. Generally, people are not educated in this confidential knowledge they are educated in external knowledge. And the king of all confidential knowledge culminates in devotional service. It is the most confidential because confidential or transcendental knowledge involves understanding the difference between the soul and the body.

Now the Lord says that this Ninth Chapter is the king of all such knowledge, the essence of all knowledge that can be derived from the study of the Vedas and different kinds of philosophy.

So there is no dearth of knowledge in the field of philosophy or transcendental knowledge. And finally there is Vyasadeva, the author of the Vedanta-sutra. Among the principal philosophers in India are Gautama, Kanada, Kapila, Yajnavalkya, Sandilya and Vaisvanara. This chapter of Bhagavad-gita is called the king of education because it is the essence of all doctrines and philosophies explained before. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya: It is everlasting, and it is joyfully performed.Д¬ommentary by Sri A.C. It is the purest knowledge, and because it gives direct perception of the self by realization, it is the perfection of religion. This knowledge is the king of education, the most secret of all secrets.

Srimad bhagavad gita chapter 2