|Brahma on his vahana, Hamsa|
One of the most powerful and most famous mantra is the Hamsa Mantra, Mantra of the with swan.
The sacred texts, one for all the Shivasutravirmasini, require that the mantra should be repeated 21,600 times.
The syllable ham is pronounced with inspiration and the syllable sa with exhalation. And since the two phases of respiration occupy about four seconds, the repetition of the mantra for 21,600 times covers a period of 24 hours, one day (86,400 seconds that is, in fact, 24 hours).
The word hamsa refers to wild goose or withe swan, among other things it is the vahana of Brahma and his wife Saraswati.
That animal is the symbol of transcendent knowledge as it can with its flight to break away from the lake as well as the man has to succeed, with the continued repetition of the mantra to break away from the illusory world of maya.
The mantra is very important for the Vedanta philosophy because hamsa refers to the words so ham (I am that) that refers to the identification of individual atman with the supreme Brahman.
The repetition (japa) of this mantra ensures the achievement of the purushatra, the four aims of life dharma, artha, kama and moksha.