Srimad Bhagavatam Canto 08, Chapter 11, Text 38

SB 8.11.38

mayasmai yad varo datto
 mrtyur naivardra-suskayoh
ato ’nyas cintaniyas te
 upayo maghavan ripoh
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The voice also said, “O Indra, because I have given this demon the benediction that he will never be killed by any weapon that is dry or moist, you have to think of another way to kill him.”
Srimad Bhagavatam Canto 08, Chapter 11, Text 37
Srimad Bhagavatam Canto 08, Chapter 11, Text 39