It was long suspected there could be interpolations in the Gita as it was being received down the ages through oral tradition. One way to scent the nature of these, if not zero in on every one of them, is to subject the text to the twin tests of sequential conformity and structural economy. Sequential conformity is all about uniformity of purpose sans digression and structural economy but represents the absence of repetitiveness. If the body Bhagavad-Gita of 700 slokas were to be scanned for possible fault lines on the above lines, the result would be but positive.
It must be realized that Bhagavad-Gita is the quintessence of the Brahmasutrãs and the Upanishads, themselves the offshoots of the Vedic spiritual roots. Those esoteric portions that relate to spiritual knowledge apart, the Vedas contain ritualistic nuances of religious ceremonies. It is the latter that has been the source of the temporal power, which the priestly class of Brahmans came to exert on the Hindu religious mind. And these very people happened to be the principal protagonists of the Gita.
It is pertinent to note that while postulating nishkãma karma, the theory of disinterested action, Krishna is critical of the ritualistic aspects of and expectations from the Vedas (s42 - 45 and s53 of ch.2.). Indeed, the guiding philosophy of the Gita is all about action, pure and simple, to tend one on the path of duty without attachment. Were the message to be allowed to percolate down, wouldn't it have hurt the Brahmans, the gods' own angels on earth as the Nãrãyana Upanishad proclaims, where it hurts most? Herein lies the provocation for them to dilute the philosophy, and the opportunity was theirs, being the repositories of the very message. Won't the priestly perks associated with the rituals of death do, to cite an example?
If upon its death, as Krishna avers, the soul were to transmigrate into another body, what for are the elaborate rituals for the dead! It is against this background that we might appreciate those interpolations that tend to advocate the ritualism on one hand, and the Brahman preeminence on the other. However, the non-application of mind on part of the Hindus who vouchsafe for these aspects of the Gita is indeed saddening.
Nevertheless, such interpolative slokas that are at variance with the avowed purpose of the Gita would show themselves up for ready pickings. In a seemingly about turn from s42- s45 and s53 of ch.2, s9-s16 of ch.3 formulate the procedural aspects of the rituals and the divine backing they enjoy. These, and such other aberrations highlighted in the prefaces of the chapters in this work were clearly the handiwork of the priestly interests to obfuscate the impact of the anti-ritualistic thrust of the Gita.
On one hand, these interpolations were meant to impart legitimacy to their creed by advocating the same through the revered text. And on the other, these were meant to stall the threat the Gita might pose to their calling in the long run. Likewise, the sprinkling of slokas that seek to confirm the prominence of the priestly class or affirm their prejudices cannot be anything but interpolations. To cap it all, are the s23-s27 of ch.8 which literally mean that if a person dies when the moon is on ascent he would attain moksha, other way round were it in descent, and such like. These slokas espousing superstition, simply put are out of tune.
Nevertheless, when interpreted figuratively they jell with the overall message of the Gita as if to prove that the discourse of reason cannot be polluted even by superstitious insertions. Be that as it may, there is an uncanny element in these artful interpolations in that they were inserted in the narrative in such a manner that if read casually they effectively merge with the text. More so for the religiously conditioned Hindu whose upbringing conforms to the ritualistic regimen!
Next is the aspect of structural economy. One finds similitude of a given content in many a sloka in the same or in a different context throughout the text. Obviously, some of them are interpolations but which were the originals and which are the imitations, may be impossible to find out for they smugly fit into the overall structure. Be that as it may, save lengthening the discourse, they do not belittle the same and fortunately not even tire the reader, thanks to the exemplary charm of Sanskrit as a language. In this context, it is relevant to note that Krishna indicated in s19, ch.10 that he would reveal a few of His Glories, but what we have is a twenty-two sloka block of the same, s 20-42, in the same chapter and another twenty, s15-s31 in the next. One can be certain that many of the slokas in them contain interpolative padding. Nevertheless, these slokas make an exciting reading notwithstanding the faux pas in s36 ch.10 where fraud in gambling is described as the Glory of the Supreme. However, s12 -s15 of ch 15 in similar vein are interpolations being digressions.
If after deliberating, one decides that the Gita is more a work of Vyãsã's genius than any divine revelation by Lord Krishna, then he or she might come to the conclusion that the concluding s78 of the last chapter meant to impart divinity to the discourse is an interpolation.
However, no exercise of this kind would be complete unless the four pairs of slokas that have the same first lines are scrutinized. With the common first line, sreyãn sva-dharmo vigunah, s35, ch.3 and s47, ch.18, seek to perpetuate caste oriented duties by discouraging any switch over, and thus are clear interpolations. S15 and s 28 of ch.6 both open with yunjann evam sadãtmãnam and the message too remains more or less the same though contextually different. Yet it appears that the former could be an interpolation. S34, ch.9 and s65, ch.18 not only start with man-manã bhava mad-bhakto but also mean same thing. In the ninth chapter as discussed in the introduction therein, s32 and s33 are clear interpolations. It also need be noted that s31 has the chapter closing character about it. Now follows this repetitive chapter-concluding sloka after two interpolations, s32 and s33. Logically speaking s34 is but an interpolation to help a proper chapter closure by slightly altering s65, ch.18. S7, ch.16 and s30, ch.18 both start with pravrurttim cha nivruttim cha line but are contextually different and thus remain above suspicion.
Identified here in this third edition are 110 slokas of deviant nature in the entire text that could be taken as interpolations with reasonable certainty. However, so as not to besmirch the general tenor of the discourse in this Treatise of Self-help, the same are interpreted in a broader perspective, but not in their narrow sense intended by the interpolators. Be that as it may, there naturally arises a hypothetical question - What if the priestly interests of yore had seen to it that the said philosophy defining slokas of the second chapter that are inimical to their creed were omitted altogether? In that case we would have been left with no option but to take the perplexing interpolations with a pinch of salt in the absence of any clue to negate them as such.