According to Yoga Explained: A New Step-by-Step Approach to Understanding and Practicing Yoga  by Mira Mehta –

“The unfamiliar actions involved in the [yoga] postures need to be assimilated into the body’s ‘memory.’ This needs time and a period of stillness. Corpse Pose (Savasana) provides such a setting. Lying down quietly, without mental or physical distractions, makes body and mind receptive to the imprints of what has been learned.”

Mira Mehta is also co-author of Yoga: The Iyengar Way.