Chapter 1, Verse 10
aparyāptam tad asmakam
balam bhiṣmābhirakṣita
paryāptam tvidam eteṣām
balam bhīmābhirakṣitam
Unlimited is this army of ours and it is marshalled by Bhishma, while the army of theirs is limited, and they depend on Bhima.
Duryodhan explained, "Our army is huge. It is very well-protected because we have Bhishma as the commander." He said, "Our army is superior in force, far superior to the Pandavas. We have Bhishma, who can't be killed. Who can kill Bhishma? Bhishma can be killed only when he wants to be killed. Nobody can remove the weapon from Bhishma's hand until he himself puts it down, which in this war, will never happen." They were very proud, very enthusiastic that Bhishma was there. It was still before the war and Bhishma was still on his feet. Duryodhan said, "Who can overrun Bhishma? Nobody!" Who can overrun the ego? The ego is so big, you know? It takes time.
Bhishma had fought great battles against Parashuram Himself and won. Parashuram was considered a great warrior, a great disciple of Lord Shiva, an incarnation of Mahavishnu Himself! Yet Parashuram Himself had lost fights with Bhishma. Bhishma was very powerful! His ego was very powerful. "How can we lose? We can't!" Duryodhan showed how great his army was, again reminding Dronacharya that, "We have more people. We will finish these Pandavas because we are more powerful." This is how the ego and pride make one believe that one is great. But humility dissipates all these other qualities.
Duryodhan continued, "It will not be a wonder if we crush their army. They really have only one strong person in their field; their army is only protected by Bhima. He is powerful, but he can be killed. Our army can't be killed, because Bhishma will die only when he wants to die. It will be easy to conquer them. We only need a great tactic. Their army is weak, vulnerable."
Bhima represents trustfulness and strength. Duryodhan said, "Bhima has got a strong body, he is very powerful, but he is not a good warrior. He doesn't have the knowledge of the army." Bhishma, on the other hand was very knowledgeable, very intelligent and wise. He had the knowledge of scriptures. He was intellectual, whereas Bhima was the opposite. Duryodhan continued, "Our army is far better, because we have the best general, Bhishma. Bhima, what does he have, apart from his big body? We can conquer the army of the Pandavas."
Bhagavad Gita