Dhritra Ashra's Power to See and Hear Everything Happening on the Battlefield

The Rishi Vyasa came to the palace to visit King Dhritra ashra. He asked if he could bestow a power that would allow him to see and hear everything happening far away on the battlefield. The king refused, because he didn't want to watch his sons die in battle. His charioteer Sanjaya was able to tell what was going on by hearing it from another side of the field.