Striking His heel into the ground, Krishna made a very large impression and then called all the holy places of the universe to pour their sacred waters in to the newly-made kunda.
One by one all the holy places arrived in their personified forms. Offering their prayers to Krishna they all poured their waters into the kunda and filled it up. Just to please Radharani, Krishna took His bath in the newly formed kunda that then became celebrated as Syama-kunda.
Exhibiting transcendental arrogance in having created such a beautiful pond, filled with the sacred waters of all the holy places in the universe, Krishna began teasing Radharani and the gopis. He said that because they were only simple village girls they must have never performed any religious duties in this world for the pleasure of the demigods. Krishna also informed them that because they sided with the demon Aristasura, in the form of a bull, they would have to share the sin of cow-killing, and must also take bath to purify themselves.
Feeling the pinch of Krishna’s joking words, Radharani suddenly exhibited Her transcendental anger and seeing a deep impression of Aristasura’s hoof print nearby, broke one of Her bangles and using it as a digging instrument, started to dig in the soft earth. Upon seeing this, the gopis also broke their bangles and started digging. Within a short time a large kunda had been created right next to Syama-kunda.
Krishna was amazed to see the large pond that Radharani and the gopis had created and made an offer to Radharani that the sacred waters from His kunda could also fill Hers. Radharani flatly refused Krishna’s offer, saying that the waters of Syama-kunda were now contaminated due to the sin of cow-killing. She further said that Her many girlfriends would form a line and bring pure waters of the Manasi-ganga in golden pots to fill her kunda.
Upon hearing the words of Srimati Radharani, the holy places personified approached Her with folded hands and while chanting beautiful prayers in glorification, humbly asked Her to grant them a boon. Radharani inquired what kind of boon they desired. The holy places personified informed Her that their lives could only be successful if they were allowed to pour their sacred waters into Her kunda also. Being ever compassionate to all those who sincerely approach Her, Radharani while glancing at Syamasundara through the corners of Her eyes, happily agreed to their proposal. In a joyous mood the holy places personified forcibly broke through the banks of Syama-kunda and poured their sacred waters into Radha-kunda.
Krishna then immediately took bath in Radha-kunda and declared that henceforth, anyone who with firm faith took a bath on that day in Radha-kunda, would achieve the same ecstatic love that Radharani had for Him. Radharani and Her girlfriends then took bath in Syama-kunda. Radharani declared that anyone who takes bath in Syama-kunda would achieve the same ecstatic love that Krishna has for Her.
This pastime occurred at 11:45 pm on the eighth day of the waning moon in the auspicious month of Kartika. Each year on this day, thousands of devotees flock to Radha-kunda for the ardha-ratri-snana (midnight bath). First they bathe in Syama-kunda and then again in Radha-kunda. This festival, held on the appearance day of Radha-kunda is known as Bahulastami. Radha-kunda is the only place in the world where a holy bath is taken at midnight.