Lord Vishnu appeared before generous King Mahabali in the form Vamana, saying that he was a famished Brahmin and desired a piece of land. At this, the king generously obliged Vamana to have as much land as he wanted in his kingdom.
Vamana made a witty retort by saying that he wanted land area covered by his three steps. King was amazed to know about poor Vamana’s intentions, but granted him the wish to go ahead with his purpose.
Soon, King Mahabali’s erudite courtesan named Shukracharya came to know that Vamana was not a person with usual means, and therefore warned king against granting the wish. However, King replied that it would be wickedness to take back the wish, which is once granted. The king, therefore requested Vamana to take the piece of land more pledged with faint idea that Vamana was no other than Lord Vishnu in disguise.
No sooner did King Mahabali make his intention clear, than Vamana gradually began to increase his body size and length and gained the size of cosmos. The poor Brahmin with his first step took entire earth into his possession, and in the next step he took entire sky in his garb. Next, Vamana asked King Mahabali where he should keep the third step, as pledged.
King Mahabali came to know that Vamana was not any ordinary Brahmin, and with his third step he would obliterate the entire earth and its existence. Generous as the king he was, Mahabali bowed before Vamana and requested him to keep the third step on his head. This will fulfill the wish granted to Vamana by him.
The poor Brahmin placed his third step on the king’s head, and he descended to the netherworld. The king now beseeched Vamana to revel his true identity, and to which he eventually agreed. Lord Vishnu appeared in his real form and told the king that he had come to test his generosity. Lord Vishnu further told that he was pleased with the commitment of King Mahabali, and granted him with divine blessing.