After Sri Krishna's death Pandava brothers relinquished their throne, after appointing Parikshit as the king of Hastinapur and Sri Krishna's great grandson (son of Aniruddha) Vajra as the ruler of Surasena and Mathura. Parikshit married Iravati, the daughter of Uttar and granddaughter of king Virata of Matsya and they had four sons including Janamejaya. Parikshit performed three aswamedha sacrices under the supervision of Kripacharya, on the banks of the Ganga.
One day while he had gone out for conquering the world, he saw a curious incident. He saw that a sudra wearing royal garments was torturing a cow and a bull. The cow was crying and the bull was consoling her. Parikshit also saw that the bull had only one leg left. He demanded to know of the Sudra why he was perpetrating such a crime under his rule. The bull then said that the wise ones believe that one's atman is the cause of happiness and misery, the fatalists blame it on destiny, the believers in karma say that one's karma determines the treatment meted out to one in a life, while materialists say that one's own nature is responsible for all happiness and sufferings, the devotional ones say that the God dispenses good or bad to individual souls based on what he or she deserves. Now the good king should judge himself as to what among this is right. The king being very wise immediately understood everything. He knew the bull to be dharma or upholder of all righteousness. The four legs are tapasya or austerity, purity, compassion and truth. In the age of Kali only truth will remain as the means of achieving righteousness, other three legs will be gone on account of pride, sensory enjoyments and excessive indulgence and now Kali is trying to deprive dharma of that last leg of truth using untruth as the means. The cow is the mother earth who is crying on account of treatment meted out to the Brahmins and the virtuous ones by the Sudras who assume the royal positions, after the passing away of Sri Krishna.
Parikshit therefore wanted to kill Kali then and there. Kali begged his life. The good king said that Kali would have to go away from his kingdom but can remain where there was gambling, drinking, adultery and violence to innocents. He also granted Kali to stay in gold and silver and other precious metals that create troubles for spiritual aspirants. He also gifted Kali with untruth, pride, indulgence and attachment, violence and enmity or jealousy. So during his lifetime Kali could not enter the world.
