Mahabharata Shalya Parva Chapter 6:2

Mahabharata Shalya Parva Chapter 6:2 In descent, in prowess, in energy, in fame, in beauty of person, and in every other accomplishment, he is superior. Mindful of the services rendered to him, he has taken up our side, having abandoned the sons of his own sister. Owning a large force of his own, that mighty-armed one is like a second (Kartikeya, the) celestial generalissimo. Making that king the commander of our forces, O best of monarchs, we will be able to gain victory, like the gods, after making the unvanquished Skanda their commander." After Drona's son had said these words, all the kings stood, surrounding Shalya, and cried victory to him. Having made up their minds for battle, they felt great joy. Then Duryodhana, alighting from his car, joined his hands and addressing Shalya, that rival of Drona and Bhishma in battle, who was on his car, said these words, "O thou that art devoted to friends, that time has now come for thy friends when intelligent men examine persons in the guise of friends as to whether they are true friends or otherwise. Brave as thou art, be thou our generalissimo at the van of our army. When thou wilt proceed to battle, the Pandavas, with their friends, will become cheerless, and the Pancalas will be depressed." "'Shalya answered, "I will, O king of the Kurus, accomplish that which thou askest me to accomplish. Everything I have—my life breath, my kingdom, my wealth—is at thy service." "'Duryodhana said, "I solicit thee with offer of the leadership of my army, O maternal uncle. O foremost of warriors, protect us incomparably, even as Skanda protected the gods in battle. O foremost of kings, thyself cause thy own self to be installed in the command as Pavaka's son Kartikeya in the command of (the forces of) the celestials. O hero, slay our foes in battle like Indra slaying the Danavas.