The Yoga of Knowledge

Krishna offers a vivid image: like a tortoise withdraws its limbs completely ('sarvaśaḥ'—from all sides) into its shell when threatened, a wise person can withdraw their senses ('indriyāṇi') from sense-objects ('indriya-arthebhyaḥ'). This isn't suppression—it's skillful mastery. The tortoise doesn't argue with danger; it simply withdraws. Then 'prajñā pratiṣṭhitā'—wisdom is established. You can engage your senses when appropriate, withdraw them when needed. That voluntary control is the mark of steady wisdom.