Srimad Bhagavatam Canto 12, Chapter 06, Text 70

SB 12.6.70

ya evemam lokam ati-karala-vadanandhakara-samjñajagara-graha-gilitam mrtakam iva vicetanam
avalokyanukampaya parama-karunika iksayaivotthapyahar ahar anusavanam sreyasi sva-dharmakhyatmava-
sthane pravartayati.
The world has been seized and swallowed by the python of darkness in its horrible mouth and has become unconscious, as if dead. But mercifully glancing upon the sleeping people of the world, you raise them up with the gift of sight. Thus you are most magnanimous. At the three sacred junctures of each day, you engage the pious in the path of ultimate good, inducing them to perform religious duties that situate them in their spiritual position.
According to Vedic culture, the three higher classes of society (the intellectual, political and mercantile sections) are formally connected with the spiritual master by initiation and receive the Gayatri mantra. This purifying mantra is chanted three times daily — at sunrise, noon and sunset. Auspicious moments for the performance of spiritual duties are calculated according to the sun’s path in the sky, and this systematic scheduling of spiritual duties is here attributed to the sun as the representative of God.
Srimad Bhagavatam Canto 12, Chapter 06, Text 69
Srimad Bhagavatam Canto 12, Chapter 06, Text 71