Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 29
Sanskrit:
विष्णोर्भगवतो भानु: कृष्णाख्योऽसौ दिवं गत: ।तदाविशत् कलिर्लोकं पापे यद् रमते जन: ॥ २९ ॥
ITRANS:
viṣṇor bhagavato bhānuḥkṛṣṇākhyo ’sau divaṁ gataḥtadāviśat kalir lokaṁpāpe yad ramate janaḥ
Translation:
The Supreme Lord, Viṣṇu, is brilliant like the sun and is known as Kṛṣṇa. When He returned to the spiritual sky, Kali entered this world, and people then began to take pleasure in sinful activities.