Srimad Bhagavatam Canto 10, Chapter 46, Text 25

SB 10.46.25

tala-trayam maha-saram
 dhanur yastim ivebha-rat
babhañjaikena hastena
 saptaham adadhad girim
 
Translation: 
 
With the ease of a royal elephant breaking a stick, Krsna broke a powerful, giant bow three talas long. He also held a mountain aloft for seven days with just one hand.
 
Purport: 
 
According to Acarya Visvanatha, a tala (“palm tree”) is a measurement of about sixty hastas, or ninety feet. Thus the great bow Krsna broke was two hundred seventy feet long.
Srimad Bhagavatam Canto 10, Chapter 46, Text 24
Srimad Bhagavatam Canto 10, Chapter 46, Text 26