Dashavatar
5 - Vamana, the dwarf. The fourth descendant of Vishnu, Bali, with devotion and penance was able to defeat Indra, the god of firmament. This humbled the other deities and extended his authority over the three worlds. The gods appealed to Vishnu for protection and he descended as a boy Vamana. During a yajna (यज्ञ) of the king, Vamana approached him and Bali promised him for whatever he asked. Vamana asked for three paces of land. Bali agreed, and the dwarf then changed his size to that of a giant Trivikrama form. With his first stride he covered the earthly realm, with the second he covered the heavenly realm thereby symbolically covering the abode of all living beings. He then took the third stride for the netherworld. Bali realized that Vamana was Vishnu incarnate. In deference, the king offered his head as the third place for Vamana to place his foot. The avatar did so and thus granted Bali immortality and making him ruler of Pathala, the netherworld. This legend appears in hymn 1.154 of the Rigveda and other Vedic as well as Puranic texts.