Narakasura was the king of Pradyoshapuram. Naraka, son of Bhudevi, got an immense power by Lord Brahma after a severe penance. But in his kingdom, the villagers suffered a lot of pains as he tortured them and also kidnapped the women to be imprisoned in his palace with his invincible might.
Now villagers started the celestial of Lord Krishna to save them from his torture as it became unbearable. But Naraka had a boon that he would face death only at the hands of his mother Bhudevi. So, Krishna requested his wife Sathyabhama, the reincarnation of Bhudevi, to be his charioteer in the battle with Naraka.
In a battle Lord Krishna hit by an arrow of Naraka and felt unconscious. Then Sathyabhama in anger takes the bow and aims the arrow at Naraka, killed him instantly. Later Lord Krishna reminds her of the boon she had sought as Bhudevi. The Narakasura Vadh by Sathyabhama gives a lesson that parents should not hesitate to punish their children when they step into the wrong path.
Reason to Celebrate Choti Diwali:
Bhudevi, mother of Naraka, declared that his son’s death should be a day of an occasion to celebrate and rejoice and of mourning. Lord Krishna bath with an oil bath to remove the blood stains from himself which spattered on his body when Naraka was killed.
The same tradition is followed people filled to the vessel in which water is being heated for having bath on the previous day of the Naraka Chaturdashi.