Verse
यदा संहरते चायं कूर्मोऽंगानीव सर्वशः ।इन्द्रियाणीन्द्रियार्थेऽभ्यस् तस्य प्रज्ञा प्रतिष्ठिता ॥
Who draws away the senses from the objects of sense, as the tortoise draws in his limbs into the shell, his intelligence sits firmly founded in wisdom.
Gītā 2·58