यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः।इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता॥
yadā sanharate cāyaṃ kūrmo ’ṅgānīva sarvaśaḥindriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā
Word by word
The verse says
When he can draw the senses back from what they reach for, the way a tortoise pulls in its limbs — then his understanding is firmly set.
In plain words
The clearest image in the chapter.
A tortoise pulls everything in. It does not fight anything, run from anything, or explain itself. It withdraws, and it can put its limbs out again.
That last part is why the image was chosen.
Where you've felt this · in family life
Someone who can genuinely stop thinking about work at the door. They have not stopped caring about it and they will pick it up again tomorrow. They can just put it down, which most people cannot.
Going deeper
The tortoise is doing more work than it first appears.
It is not armour, and it is not escape. A tortoise withdraws and then comes out again. The image is of a reversible, unforced movement — not repression, which is a limb held in by main force and quivering.
That matters because the Gita is about to say, in the very next verse, that forced abstinence does not actually work. The tortoise is being offered as the alternative: withdrawal that costs nothing because nothing is being fought.
Indriyāṇīndriyārthebhyaḥ — the senses from the objects of the senses. The Sanskrit places them side by side deliberately. The senses and their objects are made for each other; the eye and the visible are one system. The Gita never pretends that connection is unnatural.
What the settled person has is a say in it. Not a wall between the senses and the world, but the ability to disengage without a struggle — and, just as importantly, to engage again when there is something to do.
A tortoise that could only stay in would not be the image.