Krishna uses one of the most vivid and practical metaphors in the Gita. He compares the sage to a tortoise (kūrmaḥ). Just as a tortoise can immediately draw all its limbs (aṅgānīva) inside its shell from all sides (sarvaśaḥ) at the approach of danger, the yogi can withdraw their senses (indriyāṇī) from the objects of the senses (indriyārthebhyaḥ) at will. When a person has mastered this ability (yadā saṃharate), their wisdom is steady and firmly fixed.