Bhagavad Gita 6.13 Chapter 6, Verse 13

समं कायशिरोग्रीवं धारयन्नचलं स्थिरः ।
संप्रेक्ष्य नासिकाग्रं स्वं दिशश्चानवलोकयन् ॥६.१३॥

samaṃ kāyaśirogrīvaṃ dhārayannacalaṃ sthiraḥ
saṃprekṣya nāsikāgraṃ svaṃ diśaścānavalokayan

Meaning

Holding body, head and neck straight and still, steady, let him gaze at the tip of the nose without looking around.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 6.13 (Chapter 6, The Yoga of Meditation (Atma Samyama Yoga), Verse 13)