Recommend (SB cantos 5 - 7)
Srimad-Bhagavatam
SB Canto 5
It is said that yogīs always think of the Supreme Personality of Godhead within their hearts. Dhyānāvasthita-tad-gatena manasā paśyanti yaṁ yoginaḥ (SB 12.13.1). The Supreme Personality of Godhead is always observed by yogīs who practice controlling the venomous senses. As recommended in Bhagavad-gītā, yogīs should practice samprekṣya nāsikāgram, keeping their eyes half-open. If the eyes are closed completely, there will be a tendency to sleep. So-called yogīs sometimes practice a fashionable form of yoga by closing their eyes and meditating, but we have actually seen such so-called yogīs sleeping and snoring while meditating. This is not the practice of yoga. To actually practice yoga, one should keep his eyes half-open and gaze at the tip of his nose.