Srimad Bhagavatam Canto 01, Chapter 17, Text 30

SB 1.17.30

patitam padayor virah
krpaya dina-vatsalah
saranyo navadhic chlokya
aha cedam hasann iva
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Maharaja Pariksit, who was qualified to accept surrender and worthy of being sung in history, did not kill the poor surrendered and fallen Kali, but smiled compassionately, for he was kind to the poor.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Even an ordinary ksatriya does not kill a surrendered person, and what to speak of Maharaja Pariksit, who was by nature compassionate and kind to the poor. He was smiling because the artificially dressed Kali had disclosed his identity as a lower-class man, and he was thinking how ironic it was that although no one was saved from his sharp sword when he desired to kill, the poor lower-class Kali was spared by his timely surrender. Maharaja Pariksit’s glory and kindness are therefore sung in history. He was a kind and compassionate emperor, fully worthy of accepting surrender even from his enemy. Thus the personality of Kali was saved by the will of providence.
Srimad Bhagavatam Canto 01, Chapter 17, Text 29
Srimad Bhagavatam Canto 01, Chapter 17, Text 31