यथाभिवाञ्छितध्यानाच्चिरमेकतयोदितात् ।एकतत्त्वघनाभ्यासात्प्राणस्पन्दो निरुद्ध्यते
In plain words
From meditation on whatever is longed for, sustained a long while, arisen in one-pointedness; from dense practice on a single tattva -- the vibration of prāṇa is restrained.