Srimad Bhagavatam Canto 10, Chapter 50, Text 18

SB 10.50.18

tava rama yadi sraddha
 yudhyasva dhairyam udvaha
hitva va mac-charais chinnam
 deham svar yahi mam jahi
 
Translation: 
 
You, Rama, should gather Your courage and fight with me, if You think You can do it. You may either give up Your body when it is cut to pieces by my arrows, and thus attain to heaven, or else kill me.
 
Purport: 
 
According to acarya Sridhara Svami, Jarasandha suspected that Lord Balarama’s body was indestructible, and thus he offered what might be a more practical alternative, that Balarama kill Jarasandha.
Srimad Bhagavatam Canto 10, Chapter 50, Text 17
Srimad Bhagavatam Canto 10, Chapter 50, Text 19