"Exceptionally qualified daughters of powerful kings were allowed to make a choice of their own bridegrooms in open competition, and such ceremonies were called svayamvara, or selection of the bridegroom. Because the svayamvara was an open competition between the rival and valiant princes, such princes were invited by the father of the princess, and usually there were regular fights between the invited princely order in a sporting spirit. But it so happened that sometimes the belligerent princes were killed in such marriage-fighting, and the victorious prince was offered the trophy princess for whom so many princes died. Rukmini, the principal queen of Lord Krsna, was the daughter of the King of Vidarbha, who wished that his qualified and beautiful daughter be given away to Lord Krsna. But her eldest brother wanted her to be given away to King Sisupala, who happened to be a cousin of Krsna. So there was open competition, and as usual Lord Krsna emerged successful, after harassing Sisupala and other princes by His unrivalled prowess."
Srimad-Bhagavatam 1:10:29 Purport
"In that meeting, King Sisupala was also present. He was an avowed enemy of Krsna for many reasons, especially because of Krsna's having stolen Rukmini from the marriage ceremony; therefore, he could not tolerate such honor to Krsna and glorification of His qualities. Instead of being happy to hear the glories of the Lord, he became very angry. When everyone offered respect to Krsna by standing up, Sisupala remained in his seat, but when he became angry at Krsna's being honored, Sisupala stood up suddenly, and, raising his hand, began to speak very strongly and fearlessly against Lord Krsna. He spoke in such a way that Lord Krsna could hear him very distinctly.
"Ladies and gentlemen, I can appreciate now the statement of the Vedas that, after all, time is the predominating factor. In spite of all endeavors to the contrary, the time element executes its own plan without opposition. For example, one may try his best to live, but when the time for death comes, no one can check it. I see here that although there are many stalwart personalities present in this assembly, the influence of time is so strong that they have been misled by the statement of a boy who has foolishly spoken about Krsna. There are many learned sages and elderly persons present, but still they have accepted the statement of a foolish boy. This means that by the influence of time, even the intelligence of such honored persons as are present in this meeting can be misdirected. I fully agree with the respectable persons present here that they are competent enough to select the personality who can be first worshiped, but I cannot agree with the statement of a boy like Sahadeva, who has spoken so highly about Krsna and has recommended that Krsna is fit to accept the first worship in the sacrifice. I can see that in this meeting there are many personalities who have undergone great austerities, who are highly learned and who have performed many penances. By their knowledge and direction, they can deliver many persons who are suffering from the pangs of material existence. There are great rsis here whose knowledge has no bounds, as well as many self-realized persons and brahmanas also, and therefore I think that any one of them could have been selected for the first worship because they are worshipable even by the great demigods, kings and emperors. I cannot understand how you could have selected this cowherd boy, Krsna, and have left aside all these other great personalities. I think Krsna to be no better than a crow--how can He be fit to accept the first worship in this great sacrifice?
"We cannot even ascertain as yet to which caste this Krsna belongs or what His actual occupational duty is." Actually, Krsna does not belong to any caste, nor does He have to perform any occupational duty. It is stated in the Vedas that the Supreme Lord has nothing to do as His prescribed duty. Whatever has to be done on His behalf is executed by His different energies.
Sisupala continued: "Krsna does not belong to a high family. He is so independent that no one knows His principle of religious life. It appears that He is outside the jurisdiction of all religious principles. He always acts independently, not caring for the Vedic injunctions and regulative principles. Therefore He is devoid of all good qualities." Sisupala indirectly praised Krsna by saying that He is not within the jurisdiction of Vedic injunctions. This is true because He is the Supreme Personality of Godhead. That He has no qualities means that Krsna has no material qualities, and because He is the Supreme Personality of Godhead, He acts independently, not caring for conventions or social or religious principles.
Sisupala continued: "Under these circumstances, how can He be fit to accept the first worship in the sacrifice? Krsna is so foolish that He has left Mathura, which is inhabited by highly elevated persons following the Vedic culture, and He has taken shelter in the ocean, where there is not even talk of the Vedas. Instead of living openly, He has constructed a fort within the water and is living in an atmosphere where there is no discussion of Vedic knowledge. And whenever He comes out of the fort, He simply harasses the citizens like a dacoit, thief or rogue."
Sisupala went crazy because of Krsna's being elected the supreme first-worshiped person in that meeting, and he spoke so irresponsibly that it appeared that he had lost all his good fortune. Being overcast with misfortune, Sisupala continued to insult Krsna further, and Lord Krsna patiently heard him without protest. Just as a lion does not care when a flock of jackals howl, Lord Krsna remained silent and unprovoked. Krsna did not reply to even a single accusation made by Sisupala, but all the members present in the meeting, except a few who agreed with Sisupala, became very agitated because it is the duty of any respectable person not to tolerate blasphemy against God or His devotee. Some of them, who thought that they could not properly take action against Sisupala, left the assembly in protest, covering their ears with their hands in order not to hear further accusations. Thus they left the meeting condemning the actions of Sisupala. It is the Vedic injunction that whenever there is blasphemy of the Supreme Personality of Godhead, one must immediately leave. If he does not do so, he becomes bereft of his pious activities and is degraded to a lower condition of life.
All the kings present, belonging to the Kuru dynasty, Matsya dynasty, Kekaya dynasty and Srnjaya dynasty, became very angry and immediately took up their swords and shields to kill Sisupala. Sisupala was so foolish that he did not become even slightly agitated, although all the kings present were ready to kill him. He did not care to think of the pros and cons of his foolish talking, and when he saw that all the kings were ready to kill him, instead of stopping, he stood to fight with them and took up his sword and shield. When Lord Krsna saw that they were going to engage in fighting in the arena of the auspicious Rajasuya-yajna, He personally pacified them. Out of His causeless mercy He Himself decided to kill Sisupala. When Sisupala was abusing the kings who were about to attack him, Lord Krsna took up His disc, which was as sharp as the blade of a razor, and immediately separated the head of Sisupala from his body.
When Sisupala was thus killed, a great roar and howl went up from the crowd of that assembly. Taking advantage of that disturbance, the few kings who were supporters of Sisupala quickly left the assembly out of fear for their lives. But despite all this, the fortunate Sisupala's spirit soul immediately merged into the body of Lord Krsna in the presence of all members, exactly as a burning meteor falls to the surface of the globe."
Krsna Book, Chapter 74
Bhaktivedanta Book Trust. Excerpted from text and purport of HDG A.C. Bhaktivedanta Swami Srila Prabhupada.