Sutra 3.32 Immobile like a tortoise

Sutra 3.32 is in the vibhutipada, the book that discusses the exceptional faculties attained by yoga adepts. With so many people suffering sore throats around here I went looking for a sutra that pertained to the throat area. I found this one in BKS Iyengar's "Light on Pranayama". "By samyama on the pit of the throat, the yogi can make his body and mind firm and immobile like a tortoise." Who would want to be immobile like a tortoise? Or have the power to "hibernate mentally by completely immobilizing the functions of the body and intellect."? Maybe a student or anyone who works hard on mental tasks would appreciate such a rest. There are many possible interpretations of the sutras. The image of the tortoise withdrawing into its shell and not emerging until she is good and ready is a powerful one. The limbs that are withdrawn could represent many different aspects of a person. Iyengar associates them with negative emotions that are brought into a state of steadiness and transformed within the shell. I thought of the five senses and pratyahara, withdrawing the senses. We go inside in savasana, relaxation pose, and we quiet our senses. We take a break from the sensations of the world to emerge with greater freshness and steadyness of mind.