Bhagavad Gita 2.58 Chapter 2, Verse 58

यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः ।
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ॥२.५८॥

yadā saṃharate cāyaṃ kūrmo'ṅgānīva sarvaśaḥ
indriyāṇīndriyārthebhyastasya prajñā pratiṣṭhitā

Meaning

Like a tortoise drawing in its limbs, one who withdraws the senses completely from their objects has a firmly established wisdom.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 2.58 (Chapter 2, The Yoga of Knowledge (Sankhya Yoga), Verse 58)