Sanskrit
समं कायशिरोग्रीवं धारयन्नचलं स्थिरः । संप्रेक्ष्य नासिकाग्रं स्वं दिशश्चानवलोकयन् ॥
samaṃ kāyaśirogrīvaṃ dhārayann acalaṃ sthiraḥ saṃprekṣya nāsikāgraṃ svaṃ diśaś cānavalokayan
Translation
Holding the body, head and neck erect, immovably steady, looking fixedly at the point of the nose, with unseeing gaze,
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The postural details here — body, head, and neck aligned, gaze fixed at the nose-tip — are precise enough that they’re still cited as-is in modern hatha and dhyana yoga instruction. “Unseeing gaze” is the key phrase: the eyes are open and fixed on a point, but not looking outward at anything.