Bhagavad Gita Chapter 5, Verse 27 — The verse says

Krishna speaks5.27

स्पर्शान्कृत्वा बहिर्बाह्यांश्चक्षुश्चैवान्तरे भ्रुवोः।प्राणापानौ समौ कृत्वा नासाभ्यन्तरचारिणौ॥

sparśān kṛtvā bahir bāhyānś cakṣuś caivāntare bhruvoḥprāṇāpānau samau kṛtvā nāsābhyantara-cāriṇauyatendriya-mano-buddhir munir mokṣa-parāyaṇaḥvigatecchā-bhaya-krodho yaḥ sadā mukta eva saḥ

Word by word

sparśān — contacts (through senses)kṛtvā — keepingbahiḥ — outsidebāhyān — externalcakṣuḥ — eyesca — andeva — certainlyantare — betweenbhruvoḥ — of the eyebrowsprāṇa-apānau — the outgoing and incoming breathssamau — equalkṛtvā — keepingnāsa-abhyantara — within the nostrilscāriṇau — movingyata — controlledindriya — sensesmanaḥ — mindbuddhiḥ — intellectmuniḥ — the sagemokṣa — liberationparāyaṇaḥ — dedicatedvigata — freeicchā — desiresbhaya — fearkrodhaḥ — angeryaḥ — whosadā — alwaysmuktaḥ — liberatedeva — certainlysaḥ — that person

The verse says

Putting outside contacts outside, the gaze held between the brows, making the in-breath and the out-breath even as they move in the nostrils —

In plain words

A physical instruction, and the chapter has not given one before.

Contacts out. Gaze steady. Breath evened.

The sentence does not finish here. It runs straight into the next verse.

Where you've felt this · in health

You notice you have been holding your shoulders up near your ears since about nine this morning. Nobody pointed it out. The moment you notice, they come down on their own.

Going deeper

After twenty-six verses of how to stand, the chapter finally says something about what to do with your body.

That ordering is worth noticing. The technique arrives last, and it arrives short — one verse, no elaboration, no promise attached to it. Chapter 6 will take it up properly.

Prāṇāpānau samau kṛtvā — making the in-breath and out-breath even. Evening the breath rather than holding or forcing it. The same word, sama, that the chapter has used for the mind at 5.19 and for the wise seeing at 5.18.

That repetition is doing quiet work. The evenness being asked of the breath is the same evenness being described everywhere else, which suggests the body is not a separate department.

And it is the most immediately usable line in the chapter. You can even out your breathing in the next ten seconds, and you cannot make your mind even by deciding to.