Meaning of Hamsa
"Hamsa (pronounced Hum-Sa) ~ Swan; 'I am He'
Hamsa is the natural vibration of the Self, which occurs spontaneously with each incoming and outgoing breath.
By becoming aware of hamsa, a seeker experiences the identity between the individual self and the supreme Self.
Also repeated as So’ham."
~from Concise Dictionary of Indian Philosophy by Dr. John Grimes
In Indian spirituality, the swan is a symbol for the soul, as well as for the spiritual seeker endowed with discrimination.
It is said that if a mixture of water and milk is given to a swan it can drink out the milk while leaving the water behind.
This represents the ability of the practitioner to discern what is truly important in life, and to leave the rest. As the swan lives on water but its feathers are not wetted, similarly the yogi lives in the world while remaining unsullied by illusion.
"The chick knows when it breaks through the self-centered isolation of its egg that the hard shell which covered it so long was not really a part of its life. That shell is a dead thing, it has no growth, it affords no glimpse whatever of the vast beyond that lies outside it. However pleasantly perfect and rounded it may be, it must be given a blow to, it must be burst through and thereby the freedom of light and air be won, and the complete purpose of bird life be achieved. In Sanskrit, the bird has been called the twice-born. So too the person who has gone through the ceremony of the discipline of self-restraint and high thinking for a period of at least twelve years; who has come out simple in wants, pure in heart, and ready to take up all the responsibilities of life in a disinterested largeness of spirit. They are considered to have had their rebirth from the blind envelopment of self to the freedom of soul life; to have come into living relation with their surroundings; to have become at one with the All."
~Rabindranath Tagore, Sadhana