The legend is that under the rule of Mahabali, the ‘asura’ King Kerala became a paradise on earth. Indra, the Lord of Devas felt threatened and Lord Vishnu helped him to send back Mahabali to ‘Paathalam’, the neither world. Lord Vishnu took the form of a Brahmin boy Vaamana and requested Mahabali for three – foot measure of land. With a cosmic form he covered earth and the other world in two steps. For the third step the honorable king offered his head and Lord Vishnu pushes Mahabali to Paathalam, but granted him a boon to visit his land, Kerala once a year. This is Onam. From Atham day onwards flower mats are laid out on the courtyard of every household to welcome Mahabali.
On Uthradam day offering and poojas are performed to an idol of ‘Thrikkakarayappan’ (the diety of Thrikkakara temple), made out of mud, clay or wood. This ritual lasts for five days. Thiruvonam day is a day for family get together. ‘Onappudavas’ (new clothes) are gifted to family members. Onasadya a vegetarian luncheon is another specialty. A lot of cultural programmes will be held during these days.