reference: Sri Aurobindo, Savitri: a Legend and a Symbol, Book XI, The Book of Everlasting Day, Canto 1 The Soul's Choice and the Supreme Consummation
Additional Readings in Savitri can be found at https://sriaurobindostudies.wordpress.com/2023/08/28/readings-in-sri-aurobindos-savitri-a-legend-and-a-symbol/