Bhagavad Gita 1.12तस्य संजनयन्हर्षं कुरुवृद्धः पितामहः।सिंहनादं विनद्योच्चैः शङ्खं दध्मौ प्रतापवान् ॥

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 Kṛṣṇa was on the other side. But still, it was his duty to conduct the fight, and no pains would be spared in that connection.