Bhagavad-gītā As It Is · Text 2.58
Qualities of steady wisdom and sense regulation
यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः ।
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ॥ ५८ ॥
yadā saṁharate cāyaṁ
kūrmo ’ṅgānīva sarvaśaḥ
indriyāṇīndriyārthebhyas
tasya prajñā pratiṣṭhitā
One who is able to withdraw his senses from sense objects, as the tortoise draws its limbs within the shell, is firmly fixed in perfect consciousness.
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