Bhagavad Gita Chapter 2 Verse 58
भगवद् गीता अध्याय 2 श्लोक 58

यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः।
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता।।2.58।।



English Translation - Swami Sivananda
2.58 When, like the tortoise which withdraws on all sides its limbs, he withdraws his senses from the sense-objects, then his wisdom becomes steady.


English Translation of Sanskrit Commentary By Sri Shankaracharya's
2.58 And besides, yada, when; ayam, this one, the sannyasin practising steadfastness in Knowledge; samharate, fully withdraws; [Fully suggests absolute firmness in withdrawal, and withdraws suggests full control over the organs] indriyani, the senses; indriya-arthhyah, from all the objects of the senses; iva, as; kurmah, a tortoise; sarvasah, wholly (withdraws); angani, its limbs, from all sides out of fear;   when the man engaged in steadfastness to Knowledge withdraws thus, then tasya, his; prajna, wisdom; pratisthita, remains established  (the meaning of this portion has already been explained).
As to that, [That is , so far as the phenomenal world is concerned.] the organs of a sick person, too, cease to be active when the refrains from sense-objects; they get fully withdrawn like the limbs of a tortoise. but not so the hankering for those objects. How that (hankering) gets completely withdrawn is being stated:


Transliteration Bhagavad Gita 2.58Yadaa samharate chaayam kurmo’ngaaneeva sarvashah;
Indriyaaneendriyaarthebhyas tasya prajnaa pratishthitaa.


Word Meanings Bhagavad Gita 2.58yadā—when; sanharate—withdraw; cha—and; ayam—this; kūrmaḥ—tortoise; aṅgāni—limbs; iva—as; sarvaśhaḥ—fully; indriyāṇi—senses; indriya-arthebhyaḥ—from the sense objects; tasya—his; prajñā—divine wisdom; pratiṣhṭhitā—fixed in