(Though Sri Aurobindo withdrew from his physical body on December 5, 1950, the body did not show any signs of decomposition till four days later. The body was aglow with a special light which the Mother confirmed as being the light of the Supramental.)
Regarding the preservation of Sri Aurobindo’s body for several days after his withdrawal: You are right; the mere fact of preservation does not give special significance to the event. What was unique and important about the phenomenon was the presence for so many days of the Supramental Light in the body. It was the first time that the said Light was seen by many physical eyes, illumining a physical form. It was an irrefutable testimony to the fact of the great Light having concretely descended on the earth plane and found a material habitation, for however short a period. Preservation of the body by yogic means is not very uncommon. There are scores of instances of Hathayogins withdrawing their life-breath, leaving their bodies intact for days together. There are certain currents of life-force called sub-pranas in the Indian system which keep the body without disintegration even when the main life-breath has ceased. One need not be a yogi or a spiritual man or a saint for that. Persons who are used to pranayama in one form or another can have this effected in their systems.
The greatness of saints is always their own. It is not conferred on them by the beliefs or superstitions of the devotees.
- M.P. Pandit
(From “All Life is Yoga”, Dipti Publications, Sri Aurobindo Ashram, Pondicherry)