For what Lord Vishnu had to take the incarnation of Vaaman?

Answer 1

In order to destroy Bali, king of demons, Vishnu took the form of a midget, Vamana. He appeared during a huge yajna or sacrifice being conducted by the king when the latter was arrogantly distributing gifts to all who asked it to show his power and wealth. Vamana asked for just three feet of land, measured by own small feet. With the first foot Vamana, exploding in size changing from the midget into the immense god Vishnu, covered the earth. With the second he covered the heavens. When there was no place for the third foot to land, Bali, to show his humility before the god Vishnu, offered his head for Vishnu’s third foot. Vishnu third foot pushed him down into the nether regions but Bali's act of humility before Vishnu was glorified throughout the ages

Answer 2

Vamana is a personality described in the Puranic texts of Hinduism as the Fifth Avatara of Vishnu, and the first incarnation of the Second Age, or Treta yuga. Also he is the first Avatar of Vishnu which appears with a completely human form, though it was that of a dwarf brahmin. He is also sometimes known as Upendra.

The legend of Bhagavata has it that the Vamana avatar was taken by Vishnu to restore Indra's Authority over the heavens, which was taken away by force by the demon king Bali. Vamana in the disguise of a short Brahmin, carrying a wooden umbrella requested three steps of land for him to live in. Given a promise of three steps of Land by King Bali against the warning given by his Guru Sukracharya, Vamana, The Supreme God grows so huge that he could cover from heaven to earth, earth to lower worlds in two simple steps. King Bali unable to fulfil the promise of three paces of Land to the Supreme God, offers his head for the third step. Thus Vamana places his third step on King Bali's head and gives him immortality for his benevolance.

Vamana taught King Bali that arrogance and pride should be abandoned if any advancement in life is to be made, and that wealth should never be taken for granted since it can so easily be taken away. Vamana then took on the form of Mahavishnu. He was pleased by King Bali's determination and ability to keep his promise in the face of his spiritual master's curse and the prospect of losing all his wealth. Vishnu named the King Mahabali since he was a Mahatma (great soul). He allowed Mahabali to return to the spiritual sky to associate with Prahalada (the demoniac Hiranyashipu's pious son, also a descendant of the demon race) and other divine beings. Mahavishnu also declared that Mahabali would be able to rule the universe in the following yuga (age).

Bali is supposed to return every year to the land of his people, to ensure that they are prosperous. This is celebrated as the Onam festival in Kerala, where he is also called Maveli.

http://en.wikipedia.org/wiki/Vamana

Answer 3

Take a break will you? Panditji!