In plain words
Vāmana granted it. That is why, from then on, all the people of Kerala keep this festival called ‘Onam’, in the faith, ‘Emperor Bali has appeared in our kingdom.’ But there is another inner meaning in this ‘Onam’. What does ‘Onam’ mean? Is it wearing new clothes? Does wearing new clothes alone make it Onam? Cloth stands for the heart. Wearing new clothes means putting away the old and the loathsome and putting on a heart that is new, splendid and fresh! On Onam they clean all their houses, tie festoons of green leaves, tie up banana plants and decorate in many ways. What is the inner meaning of this?
The inner meaning of the Onam festival is to cleanse the outer house and the inner heart and live with a heart that is pure, steady and selfless
‘Antarbahiścatatsarvam vyāpya nārāyaṇasthitaḥ’: God dwells within and without. So the true meaning of this festival is to clean the outer house, to cleanse the inner heart as well, and to remain with a heart that is pure, steady and selfless. Besides this, there is another, scientific meaning too. In the old days the houses in Kerala had no doors or windows, no way for the air to come in and go out, and were very cramped. In the land of Kerala the rains fell heavily. So, to keep warm, they built them with small doorways and few windows. On these festival days they tied festoons of green mango leaves to the house, wove tender coconut leaves into decorations, tied up banana plants and decorated in many ways. This is not merely outward decoration; there is a scientific benefit in it too. What is that benefit? These green leaves take in the carbon dioxide that man breathes out. The green leaves give men the oxygen they release.