Krishna has been describing the sthitaprajña, the person whose understanding has settled. Here he offers one of his most precise images: the tortoise pulling its limbs inward, as a metaphor for what actually happens when the senses are withdrawn.
yadā saṃharate cāyaṃ kūrmo'ṅgānīva sarvaśaḥ | indriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā ||
Just as a tortoise withdraws all its limbs fully into its shell, when a person withdraws the senses completely from their sense-objects, that person's wisdom (prajñā) is said to be steady and established.
This verse is often read as an instruction to suppress or deaden the senses. That reading is wrong. The tortoise image is specifically about an available capacity, not a permanent state of retraction. The person with steady prajñā can engage fully and withdraw fully. The freedom is in the ability to do either, not in choosing one permanently.
In terms of actual inner experience, what is being withdrawn is attention, not the sensory apparatus itself. You hear the sound either way. The difference is whether attention flows into it automatically, gets caught by it, starts following it. The withdrawal is a movement of the faculty that allocates attention, not a shutting of the ears or eyes.
Krishna is not prescribing a technique here. He is describing what a settled intelligence looks like from the outside. The tortoise withdraws because it is a tortoise. A person with stable prajñā can withdraw because the intelligence is no longer fully governed by appetite. The description is diagnostic before it is prescriptive.
Most people's senses operate on pure autopilot: something shiny appears, attention latches. A notification arrives, the hand moves. A threat appears, the body tightens. What this verse describes is the interruption of that automation. Not a refusal to act, but a gap between stimulus and response where something other than habit can operate.
Person A sits down to work. Notifications are on. The phone is on the desk. Within two minutes of opening a document, they are three tabs deep into something that arrived. An hour later, they surface, mildly annoyed at themselves, with the original task untouched. The senses ran the session. The person was along for the ride. Person B sits down to the same situation. They notice the pull of the notification. They feel it, register it as a pull, and consciously do not follow it. The notification is still there, the urge is still there. What is different is that something in Person B has not automatically extended toward the object. The limb stayed in. The task gets done. Person B is not a saint. They are just someone in whom one layer of autopilot has been interrupted.
Verse 2.59 moves one step deeper: even when you forcibly stop engaging with sense-objects, the taste for them lingers. Krishna now addresses what actually shifts that lingering pull, not just the outward behavior. When ready, say: "2.59"