The 21st chapter is a continuation of the discourse started in the 20th chapter. The Lord tells Uddhava that those who abandon all the three paths of jnana, karma and bhakti, and enjoy the trifling pleasures of senses undergo transmigration.
Even though all substances are constituted of the same five basic elements and hence similar, they are termed as pure, impure, auspicious, virtuous ,wicked etc in accordance with the presence or absence in them of the special attributes of the Lord, and not due to any difference in their basic nature. These pairs of opposites are to be seen in people’s conduct in all spheres of life e.g. religion, commerce, pilgrimage etc; these are specially stressed by the Lord for the benefit of those bearing the responsibility for upholding Dharma.
The diversity represented by the names and forms of the created beings from the pure to impure, good to bad etc; which exhibit opposing traits among a homogeneous base is due to varying presence in them of the attributes of Sri Hari, and is meant to secure their ultimate objective of liberation. The varying attributes of different activities, the place where they happen, time of happening and substances used are then brought out in detail by the Lord, for the purpose of regulation of different actions. Some acts even if done according to prescribed regulations but by non devotees (without reverence) will lead to displeasure of Sri Hari and will render the act impure. Some acts, which appear to be impure (such as killing of Vritra- a Brahmin), as they lead to the pleasure of Sri Hari, become pure. The regulations governing pure and impure acts and their resultant fruits viz heaven and hell, are applicable and binding on those who can (and ought to) understand them.
To the extent that the actions are undertaken by one without false ego and with the intent to please Sri Hari, such actions do not bind him. When man develops excessive attachment to sense pleasures, his judgment is clouded leading to wasted life. Such a person knows neither himself nor the Supreme, lives in vain like a tree and breathes like the bellows. Therefore, as contemplation on sense pleasures leads ultimately to disaster, one should not hanker after pleasures, including those of heaven.
The promise of glowing rewards in the Vedas in fact refers to the final beautitude (moksha) and not to the transitory benefit of heaven etc. However in the case of aspirants who are at the lower rings of their spiritual sadhana, the apparent references to the alluring heavenly pleasures in such promises, are for inducing those aspirants to persist in their striving, as in the case of a sweetener added to a dose of bitter medicine so as to induce a stubborn child to take it (which will cure its illness).
An authority of Divine Wisdom such as the Vedas will certainly not hold out the trifling pleasures of heaven, to be the ultimate objective to be sought by the aspirant. Even though the Vedas, on a superficial reading, appear to deal with three different topics viz rituals, godheads and the Supreme Lord, to the qualified and discerning aspirant, they (the Vedas) expound extensively the all perfect nature of the Supreme Lord. The Veda thus conveys its meaning only indirectly and such indirect mode of revelation is dear to the Lord, since only the pure hearted are enabled to reach Him (keeping out the ineligible). The Vedas expounding the Lord could be perceived by the wise in the form of the anahata sound in all created beings like the fiber in the lotus stalk. Just as the spider sends forth the filaments of the cobweb from its heart through its mouth (and at the end withdraws the web back into its heart), so Mukhya Prana who with theLord’s grace is capable of awarding liberation, at the beginning of creation, imparts to Rudra and others, the Vedas which propound the Lord and which is made up of innumerable branches; and at the end of the Kalpa, withdraws the same back into Himself.
The various sounds as well as the amazing languages put forth by the Vedas such as guhya, darshana and samadhi are mentioned; as well as the consonants of the alphabet. What the Vedas lay down in the matter of rituals, mantras, upasana and jnana, is known fully only by Sri Hari and by none other. Thus all Vedas expound Sri Hari alone in all His manifestations and avataras. They prescribe for the living being-who gets this wonderful human body as willed by the Lord- a regime for the worship of Sri Hari consisting of injunctions and interdictions by which He could, in due course, be realized. Such realization leads to moksha at which point there is no longer the need for the gross body. In liberation, the Vedas continue to expound Sri Hari but fall silent on the injunctions and interdictions (which are no longer necessary). Thus ends the twenty first chapter.