Chapter II · Śloka 58
यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः |
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ||
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ||
yadā saṃharate cāyaṃ kūrmo'ṅgānīva sarvaśaḥ |
indriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā ||
indriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā ||
When one completely withdraws the senses from their objects, as a tortoise draws its limbs into its shell, then one's wisdom is firmly established.
The kūrma (tortoise) simile is one of the Gita's most memorable images: withdrawal is not cutting off the limbs but the organic retraction of what is already one's own. The senses are not destroyed but mastered — available when needed, retracted by choice.