Kamsa out of the love he bore for his sister decided to be the bride and groom’s charioteer for the day. While Kamsa drove the chariot bearing Devaki and Vasudeva out of the wedding hall, a voice from the heavens boomed informing Kamsa that Devaki’s eight child would be his slayer.
Story of Lord Krishna birth:
Kamsa being the superstitious type would take no chances. He wanted to strike down Devaki that very moment. Vasudeva intervened, he begged Kamsa not to slay Devaki and show her some mercy. He further promised Kamsa that he would hand over any child born to them, if he would let Devaki live. Now Kamsa not wanting to have the blood of his sister on his hands agreed and instead placed them under house arrest.
Every time a child was born, the guards would inform Kamsa and he would take the child and kill it. Six of Devaki and Vasudev’s children met their death this way. It so happened that the seventh child was born at night, and Devaki and Vasudeva seeing the opportunity decided to try to save the child.
The guards were asleep, so Vasudeva easily slid out of the palace undetected. He went to neighboring Gokul and left the child with his second wife Rohini and quickly returned to the palace (this child was named Balrama). In the morning he sent word to Kamsa that the child was still born.
Kamsa was pleased, he knew the next child was prophesized to be his slayer. Not wanting to take chances with the birth of the eight child, Kamsa had Vasudeva and Devaki thrown into the dungeon chained.
The 8th child was born on the eight night of the month of Shravan. It was raining heavily and the skies thundered as if the Gods were trying to pay homage to the new born child. Then the miracle happened, Vasudeva’s chains fell off and the prison door opened by itself. Vasudeva found the guards to be asleep, so he decided that he would escape with the child and leave him at his friend Nanda’s place in Gokul.
Picking up the child, Vasudeva placed him in a basket. He then carried the basket on his head and made his way to Gokul. Now Gokul was on the opposite bank of the river Yamuna. Because of the thundering and the rain, the river Yamuna was in a state of turmoil. Vasudeva, wondering how he would cross the river prayed for a miracle. Then it happened!. The waters of the Yamuna parted and made way for him. Vasudeva then crossed the Yamuna and reached Gokul.
On reaching Nanda’s house in Gokul, Vasudeva realized that Nanda’s wife Yashoda had given birth to a baby girl. While Nanda and Yashoda were asleep, he placed his child in the cradle and took Nanda’s daughter instead. He presumed that since it was a baby girl, Kamsa would not kill her. He then made the journey back to Mathura and he took the baby girl with him. As soon as Vasudeva reached the dungeon, the dungeon doors closed behind him and the baby girl started to cry. Awakened by the cries, the guards rushed to tell Kamsa of the birth of the eight child.
Hearing the news, Kamsa rushed to the dungeon and picked up the child and was about to dash it to the ground. Vasudeva begged Kamsa not to kill the child as it was only a girl and that a girl could do him no harm. The wicked Kamsa paid no heed and dashed the baby to the floor. As the baby was about to hit the floor, it suddenly flew up and told Kamsa that the one who was born to kill him still lives and is in Gokul. Then she disappeared.