BG 2.58
यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः ।
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ॥
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ॥
yadā saṁharate cāyaṁ kūrmo ’ṅgānīva sarvaśaḥ
indriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā
indriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā
Word-for-word meanings
yadā ca — and when; ayam — he [the sage]; sarvaśaḥ — completely; saṁharate — withdraws; indriyāṇi — [his] senses; indriya-arthebhyaḥ — from the sense objects; aṅgāni iva — like the [withdrawn] limbs; kūrmaḥ — of a tortoise; tasya — his; prajñā — wisdom; pratiṣṭhitā — becomes stable.
Translation
When the sage completely withdraws all his senses from the sense objects, as a tortoise draws its limbs within its shell, his wisdom becomes stable.