In the chapter 13 dealing with the Kshetra (Field)and Kshetrajña (Field-knower), it was shown after an examination of the nature of Prakrti and the self, that the beginningless conjunction of the pure self consisting only of infinite knowledge, with the Prakrti transformed into the forms of gods etc., causes the flow of attachment to the Gunas of the Prakrti. In the next chapter (14) the following points were treated: (1) The conjunction of the self with the Prakrti in its two states of effect and cause has attachment to the Gunas for its source and it is determined by the Lord Himself; (2) The manner of attachment to the Gunas has been stated in detail; (3) The attainment of the true nature of the self preceded by the annihilation of attachment to the Gunas has devotion to the Lord as its means. All these have been discussed. Now (in the 15th chapter), Shri Krishna begins to speak of the adorable Lord as having absolute control of the universe consisting of perishable (Kshara) or bound selves and the imperishable (Akshara) or freed selves. He also states that the Lord is the Supreme Person because of his supreme greatness in being antagonistic to all that is evil and in being endowed with auspicious attributes which are different in kind from both the perishable and imperishable selves and which constitute His glory. Then to elucidate the manifestation called Akshara (or freed souls) whose bondage has been cut off by the sword of non-attachment, the Lord describes the modification of Kshara or non-intelligent Prakrti into the form of bondage that has to be cut off. This modification of bondage-creating Prakrti is compared to the Ashvattha (Pipal tree or ficus religious) in the verses that follow.

The Vedas speak of the imperishable ‘Ashvattha tree’ called Samsara, which has its ‘roots above and branches below’, in such passages as the following: ‘This Ashvattha tree with its roots above and branches below is eternal’ (Ka.U., 6.1), and ‘He who knows the tree with its roots above and branches below’ (Tai.A., 1.11.5). It has its roots above since it has its roots in Brahma (the Creator otherwise known as Hiranyagarbha) who is seated above the seven worlds. It has ‘branches below’ ending with denizens like men, animals, beasts, worms, insects, birds and immovables. It is ‘immutable’ since it cannot be felled, being of the form of a continual flow. It can be felled only at the dawn of perfect knowledge which causes detachment. They say that the leaves of this Ashavattha tree constitute the Vedas. ‘The Vedas are said to be the leaves’, since this tree of Samsara increases by actions prompted by worldly desires as taught in certain Shrutis as, ‘He who desires prosperity should sacrifice a white animal to Vayu’ (Taitt.Sam., 2.1.1) and ‘The desirer of offspring shall offer to Indra and Agni a sacrifice with eleven cups of rice-cakes’ (Ibid., 2.2.1). Indeed the tree flourishes with the help of leaves. He who knows the Ashvattha of such a nature ‘knows the Vedas’. The Vedas also set forth the means of felling this tree of Samsara. He who understands this is called the knower of the Vedas, since knowledge of the nature of the tree to be cut off is helpful to the knowledge concerning the means of felling the tree.

Its branches extend both above and below, nourished by the Gunas. Their shoots are sense objects....

This tree spreads downward with men etc., who are the products of their Karma, as branches. It again spreads above into Gandharvas, Yakshas, gods, etc. They are nourished by the Gunas of Sattva etc. They have tender shoots augmented by sense-objects. How does this happen? Shri Krishna explains: