Bhismadev tried to cheer Duryodhana (Chapter 1 Text 12)
Chapter 1: Observing the Armies on the Battlefield of Kuruksetra
tasya sanjanayan harsam
sankham dadhmau pratapavan
tasya--his; sanjanayan--increasing; harsam--cheerfulness; kuru-vrddhah--the grandsire of the Kuru dynasty (Bhisma); pitamahah--the
grandfather; simha-nadam--roaring sound, like a lion; vinadya--vibrating; uccaih--very loudly; sankham--conchshell; dadhmau--blew;
Then Bhisma, the great valiant grandsire of the Kuru dynasty, the grandfather of the fighters, blew his conchshell very loudly, like the
sound of a lion, giving Duryodhana joy.
The grandsire of the Kuru dynasty could understand the inner meaning of the heart of his grandson Duryodhana, and out of his natural compassion
for him he tried to cheer him by blowing his conchshell very loudly, befitting his position as a lion. Indirectly, by the symbolism of the conchshell, he informed his depressed grandson Duryodhana that he had no chance of victory in the battle, because the Supreme Lord Krsna was on the other side. But still, it was his duty to conduct the fight, and no pains would be spared in that connection.
Source: As It Is by HDG. A.C. BhaktiVedanta Swami Srila Prabhupada