Is there any story behind Lord Krishna’s death?
The story of Krishna's death is told in the Mausala Parva of the Mahabharata, but what led up to it starts earlier, in the Stri Parva. Right after the Mahabharata war, when Gandhari went to the battlefield of Kurukshetra where her sons' bodies were lying dead, she was overcome with anger at Krishna for not stopping such a deadly war, so she gave him the following curse:
Since thou wert indifferent to the Kurus and the Pandavas whilst they slew each other, therefore, O Govinda, thou shalt be the slayer of thy own kinsmen! In the thirty-sixth year from this, O slayer of Madhu, thou shalt, after causing the slaughter of thy kinsmen and friends and sons, perish by disgusting means in the wilderness. The ladies of thy race, deprived of sons, kinsmen, and friends, shall weep and cry even as these ladies of the Bharata race.
Krishna accepted the curse willingly, because it was all part of his divine plan to eliminate the Yadava race who had become a burden on the earth.
But the sequence of events immediately leading up to the Krishna's death is described in the Mausala Parva. 36 years after the Mahabharata war, the sages Vishwamitra, Kanva, and Narada came to Dwaraka, and Krishna's son Samba along with his friends decided to play a trick on the sages. They dressed up Samba as a woman, and asked the sages what kind of son this woman would have. The sages saw through the disguise, and enraged by this act of disrespect, they issued the following curse:
This heir of Vasudeva, by name Samba, will bring forth a fierce iron bolt for the destruction of the Vrishnis and the Andhakas. Ye wicked and cruel ones, intoxicated with pride, through that iron bolt ye will become the exterminators of your race with the exception of Rama and Janarddana. The blessed hero armed with the plough will enter the ocean, casting off his body, while a hunter of the name of Jara will pierce the high-souled Krishna while lying on the ground.
And indeed, the next day Samba really did give birth to an iron bolt! When Ugrasena (the king of Dwaraka) heard about this, he ordered his men to make the bolt into a fine powder and then throw the powder into the sea. And the production of alcohol was banned, because the curse mentioned that the Yadavas would destroy their own race while drunk.
But then shortly thereafter, the entire Yadava race went to the sea coast to bathe in the sacred waters of Prabhasa, and there they started to drink. A drunken brawl soon ensued, and lacking weapons they started plucking Eraka grass out of the ground, which magically transformed into iron bolts with the power of thunder:
Indeed ... whoever amongst them took up in wrath a few blades of the Eraka grass, these, in his hands, became soon converted into a thunderbolt... Every blade of grass there was seen to be converted into a terrible iron bolt. All this ... was due to the curse denounced by Brahmanas. He who hurled a blade of grass saw that it pierced through even such things as were utterly impenetrable. In fact, every blade was seen to become a terrible bolt having the force of thunder.
You see, some of the powder from the iron bolt of Samba had washed up on the shore of Prabhasa and had magically grown into that Eraka grass. In any case, using the weapons furnished by the grass, the Yadavas soon annihilated each other. Then Krishna's brother Balarama started engaging in meditation and soon gave up his body, turning back into Vishnu's serpent Adiseshan:
Proceeding then to the forest, Keshava [i.e. Krishna] beheld Rama sitting in a solitary spot thereof. He also saw that Rama had set himself to Yoga and that from out his mouth was issuing a mighty snake. The colour of that snake was white. Leaving the human body (in which he had dwelt so long), that high-souled naga of a 1,000 heads and having a form as large as that of a mountain, endued besides with red eyes, proceeded along that way which led to the ocean.
Krishna then sat down in the forest, knowing that it was time for him to depart the earth. He was shot by the hunter Jara, who mistook Krishna's left foot for the mouth of a deer:
A fierce hunter of the name of Jara then came there, desirous of deer. The hunter, mistaking Keshava, who was stretched on the earth in high Yoga, for a deer, pierced him at the heel with a shaft and quickly came to that spot for capturing his prey. Coming up, Jara beheld a man dressed in yellow robes, rapt in Yoga and endued with many arms. Regarding himself an offender, and filled with fear, he touched the feet of Keshava. The high-souled one comforted him and then ascended upwards, filling the entire welkin with splendour. When he reached Heaven, Vasava and the twin Ashvinis and Rudra and the Adityas and the Vasus and the Viswedevas, and Munis and Siddhas and many foremost ones among the Gandharvas, with the Apsaras, advanced to receive him.
Jara's shaft was made of the remaining powder of Samba's iron bolt, which had been swallowed by a fish, where it had solidified into a piece of iron. Jara caught the fish and made the iron into a shaft for hunting. Thus, just as the sages had prophesied, Krishna and his Yadava clan were destroyed by an iron bolt.
By the way, it is said that Jara was the reincarnation of Sugriva's brother Vali, whom Vishnu had killed from behind in his incarnation as Rama, so Jara was killing Krishna the way Rama had killed Vali.
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