Death, in Savitri, represents the quintessence of the Dark Inconsccient whose chief business is to prevent material existence from growing divine. Yet matter has grown from the mineral rock to man because hidden within its folds is the Divine Himself as the evolutionary Force, the Divine Shakti pushing from within, from behind, from below through the veils of Nature. Death, therefore, is the Resistance offered to the divine manifestation that is the original Will and for which earth was made and towards which man has been chosen as a conscious collaborator. As evolution proceeds, death too tries to spread its net on all matter-based life. He puts a veil over creation so to say. In man he enters our ignorant and confused thoughts blinding us to the Divine Presence, denying God or else admitting only that much of God as would take us away from material existence into some otherworldly impersonal existence. He keeps us tied to the duality of good and evil with the reward of earthly goods that keep us tied to ignorance and punishment for too high an aspiration by snatching away material possessions which is his stronghold.
Perhaps Yama has been taken in this sense as the Restrainer. He restrains our evolutionary journey by posing laws that are binding even to the gods when they enter his fortress, the bodily life. He is a guardian of the law. The original law however was meant to be a straight and sunlit climb, it is the law of Truth, Satyadharmaye. Yama is the son of Sun and Shadow (Chaya) which suggests that he is a fallen angel and to convert him back to his original status is one of the works of the incarnate Divine. Even in the traditional story, if we look at it from this New Light we shall see the hint of conversion of the Asura of Death, Yamaraj, the Restrainer, into Dharmaraj, the guardian of the law of Truth.
In Savitri Sri Aurobindo reveals the various ways he works to limit and block man’s further evolution occupying his thoughts by using reason to deny the very existence of what has built up Reason in our brains, through various systems of philosophy that create an unbridgeable gulf between the material life and the spiritual life. He twists the truth and thereby turns it into a lie. He denies the very existence of Love which is the One Power labouring to save creation from chaos since the origin. But his strongest field where he still holds his fort is matter and all that is based on matter. This is so because matter is the first direct result of the presence of the Divine in the Inconscient. The Inconscient, therefore, has a great hold upon it. Therefore will the conquest of matter and material life the last crown of the Victory.
Right now matter has released from itself the forces of life and mind. Now matter is preparing to release from within the Supermind subsequent to the events of 5th December 1950 (Supramental descent) and of the 29th February 1956 (supramental manifestation). It means that the bodily life will come more and more under the influence of the Supermind which alone can activate the law of Truth (Satyadharmaye) replacing it with the law of death that presently governs us. Of course this too was needed as a preparation. But this phase of evolution is over, at least for some individuals who are now ready to evolve directly by an opening to the Light rather than indirectly receive it through the shadowy veils of Darkness. The conquest over physical death will be the last sign of this victory of the Law of Truth, Satyameva Jayate, over the earth. So as we see it is not just escaping the law of Death and realising some kind of immortality on the subtle plane where death is not strong enough, but to change the law and conditions of material life and earthly evolution into a spontaneous divine efflorescence so that body responds to the New Consciousness without any resistance thereby realising its divinity and with it, and as a consequence, the immortality.
In the story of Savitri, it was an individual possibility and still only for a term (Satyavan lived for 400 years according to the legend). Yet it was a promise. Now the original project has been taken up on a larger collective scale towards a definitive and complete victory of the Power of Love labouring in creation over Death that has resisted the advance at every level thereby retarding the evolutionary journey filling it with blocks and challenges and stumbles and errors upon the way. However, in the last analysis, this too was part of the plan, the resistance contributing to a greater perfection.
So as we see at the end Death too is a mask that the Eternal has assumed to serve as a goad towards Immortality.
About Savitri | B1C3-07 Workings of the New Consciousness (p.28)