When one can draw the senses back from their objects on every side, as a tortoise draws in its limbs, that person's wisdom stands firm.
Explanation
Krishna is answering Arjuna's question about the person of steady wisdom (sthitaprajña). Here he gives an image: like a tortoise withdrawing its limbs, such a person can pull the senses (indriya) back from sense objects at will. Wisdom (prajñā) is steady when the senses are under this kind of inner control. Commentators differ on whether this means outward restraint or an inner turning away from craving, but all agree it describes mastery, not suppression alone.