To the ordinary human understanding and sight, Sri Aurobindo is said to have passed away on the 5th day of December 1950. Several persons have described this as the passing away of The Master— an Event that seemed to bring huge shadows of sorrows on the followers of The Master and The Mother. People in huge numbers paid their last respects to Him, till the 9th day of December 1950.
To men in general, it was only, or mainly, a departure, a passing away, as billions and billions of humans have passed away since the beginning of the human race.
However, indeed, it was a sacrifice — a sacrifice of the physical being of The Master, a sacrifice made by Himself, so that the Supramental Consciousness and Force may descend to the physical plane. The Supermind descended and the consequence was the Sacrifice of the physical being of Sri Aurobindo, mainly due to the lack of receptivity of the earth and the people.
The Mother said on 8th December 1950: The lack of receptivity of the earth and men is mostly responsible for the decision Sri Aurobindo has taken regarding his body. But one thing is certain: what has happened on the physical plane affects in no way the truth of his teaching. All that he has said is perfectly true and remains so. Time and the course of events will prove it abundantly.
The Mother has again said 29th December 1950: Our Lord has sacrificed himself totally for us ... ... He was not compelled to leave his body, he chose to do so for reasons so sublime that they are beyond the reach of human mentality ... ... And when we cannot understand, the only thing is to keep a respectful silence.
The Mother has also told that Sri Aurobindo is always present on earth for the progress and advancement of the Evolution — from Man to the Supramental Being.
On the 7th day of December 1950, She said:
Lord, this morning Thou hast given me the assurance that Thou wouldst stay with us until Thy work is achieved, not only as a consciousness which guides and illumines but also as a dynamic Presence in action. In unmistaken terms Thou hast promised that all of Thyself would remain here and not leave the earth atmosphere until earth is transformed. Grant that we may be worthy of this Presence and henceforth everything in us be concentrated to the fulfilment of Thy sublime work.
Again on 18th January 1951, She said: We stand in the Presence of Him who has sacrificed His physical life in order to help more fully His Work of Transformation.
He is always with us, aware of what we are, of all our thoughts, of all our feelings and all our actions.
On His leaving of His Physical body, the Supramental Consciousness descended in the physical being of The Mother — and then began the preparation for the Descent of the Supramental Consciousness on earth, which actually took place on 29th February 1956.
The purpose for which Sri Aurobindo came to Pondicherry was the Descent of the Supramental Consciousness on earth and make Supermind a part of the earthly nature, as Life and Mind are parts of nature on earth. Nature is evolutionary and as Life and Mind have manifested through an evolutionary process, so will Supermind manifest on earth. And that is the Work of Sri Aurobindo — a Total Transformation.
The Descent of Supermind had a requirement that there shall be an Ascent to the Supramental Plane. Only after the Ascent, the Task of the Supramental Descent was taken by The Master. Even in 1938, Supermind used to descend in the physical being of The Master. But It was not settled then in His physical Mind or in His physical being.
When Supermind descends into a human being, It creates a Mind of Light, a Pure Mind reflecting and radiating the Light and Consciousness and Force, as stated and explained by Sri Aurobindo in The Supramental Manifestation upon Earth.
The Mother said that "as soon as Sri Aurobindo withdrew from His body, what He called the Mind of Light got realized here." And the Mind of Light manifested in The Mother.
As soon as the Supramental Consciousness descended on Him, Sri Aurobindo left His body with a view to concentrate on His Work: The Supramental Manifestation on earth. The Work of the Supramental Manifestation intensified with the so-called passing away of Sri Aurobindo. And Sri Aurobindo's physical Withdrawal was greatly successful when on the 29th February 1956, The Mother caused an uninterrupted flow of the Supramental Consciousness and Force upon earth.
The Work of The Mother and Sri Aurobindo is going on, led by Them.
The Mother has said on 15 April 1972 :
The transition from man to the supramental being is accomplished through the superman. There may be a few superman- there are -who will actually make that transition. [Mother's Agenda, vol. 13]
The Mother differentiated between the Supramental Being and the Superman. The Supramental Being will have a Supramental Body.