द्वादशाङ्गुलपर्यन्ते नासाग्रे विमलाम्बरे ।संविद्दृशि प्रशाम्यन्त्यां प्राणस्पन्दो निरुद्ध्यते
In plain words
At the tip of the nose, in the clear space extending twelve fingers' breadth beyond it; when the gaze of saṃvid grows still there -- the vibration of prāṇa is restrained.