Bhagavad Gita Chapter 6, Verse 13

समं कायशिरोग्रीवं धारयन्नचलं स्थिरः | सम्प्रेक्ष्य नासिकाग्रं स्वं दिशश्चानवलोकयन् ||

samaṁ kāya-śiro-grīvaṁ dhārayann acalaṁ sthiraḥ samprekṣya nāsikāgraṁ svaṁ diśaś cānavalokayan

Holding the body, head, and neck erect and still, gazing at the tip of one's nose without looking around.

Krishna describes the physical posture and gaze for meditation. 'Samaṁ kāya-śiro-grīvaṁ dhārayan'—holding (dhārayan) the body (kāya), head (śiraḥ), and neck (grīva) straight (samaṁ). This means: the spine should be erect, the head and neck aligned with the body—straight posture, not slouched. 'Acalaṁ sthiraḥ'—motionless (acalam) and steady (sthiraḥ). This means: once you're in the correct posture, hold it steady—don't fidget, don't move, remain still. 'Samprekṣya nāsikāgraṁ svam'—gazing (samprekṣya) at the tip of one's own (svam) nose (nāsikāgram). This means: focus your eyes on the tip of your nose—this helps concentrate the mind. 'Diśaś cānavalokayan'—without looking around (anavalokayan) at the directions (diśaḥ). This means: don't let your eyes wander—keep them focused on the nose tip, not looking around. The posture and gaze support the one-pointed mind—a steady body and focused gaze help maintain concentration.