Duryodhana performing the Vaishnava Yajna is an interpolated episode in the Mahabharata.
This interpolated story appears in the 255th to 256th chapters of Vana Parva.
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The narration of this interpolated story is as follows:
- Duryodhana reaches Hastinapura, after getting defeated, captured and releasedby Gandharvas in the Ghosha Yatra,
- Karna consoles Duryodhana and seeks permission for his Digvijaya Yatra,
- Karna’s Digvijaya Yatra (narrated in 253rd and 254th chapters of Vana Parva),
- Duryodhana’s proposal to perform Rajasuya Yagna,
- Purohita of Duryodhana advising him that he cannot perform Rajasuya Yagna, as long as Yudhisthira is alive, and suggesting to perform Vaishnava Yagna, which was performed by Vishnu himself and thus, which is equivalent to Rajasuya Yagna
- Duryodhana performing Vaishnava Yagna.
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In view of the following reasons, I have inferred that Duryodhana performing Vaishnava Yagna is an interpolation.
a) Duryodhana performing Vaishnava Yagna was after Karna’s digvijaya Yatra. As Karna’s Yatra itself an interpolation, the episode of performing Vaishnava Yagna is also an interpolation.
b) When Krishna narrates the pros and cons in undertaking Rajasuya Yagna to Yudhisthira (Sabha Parva) and about the strength of Jarasandha, Yudhisthira expresses his view for not to venture into performing that Rajasuya Yagna.
At that point of time, Krishna did not suggest to him to perform Vaishnava Yagna, which according to the Purohita of Duryodhana, is equivalent to Rajasuya Yagna. If Krishna is aware of the potency of the Vaishnava Yagna, he should have recommended that Yagna to Yudhisthira, who was dithering at that point of point of time.
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Hence, according to my understanding, the episode of Duryodhana performing Vaishnava Yagna is an interpolation.