Srimad Bhagavatam Canto 07, Chapter 01, Text 19

SB 7.1.19

sapator asakrd visnum
 yad brahma param avyayam
svitro na jato jihvayam
 nandham vivisatus tamah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Although these two men — Sisupala and Dantavakra — repeatedly blasphemed the Supreme Personality of Godhead, Lord Visnu [Krsna], the Supreme Brahman, they were quite healthy. Indeed, their tongues were not attacked by white leprosy, nor did they enter the darkest region of hellish life. We are certainly most surprised by this.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Krsna is described by Arjuna in Bhagavad-gita (10.12) as follows: param brahma param dhama pavitram paramam bhavan. “You are the Supreme Brahman, the supreme abode and purifier.” Herein this is confirmed. Visnum yad brahma param avyayam. The Supreme Visnu is Krsna. Krsna is the cause of Visnu, not vice versa. Similarly, Brahman is not the cause of Krsna; Krsna is the cause of Brahman. Therefore Krsna is the Parabrahman (yad brahma param avyayam).
Srimad Bhagavatam Canto 07, Chapter 01, Text 18
Srimad Bhagavatam Canto 07, Chapter 01, Text 20