Mahabharata Drona Parva Chapter 12:2

Mahabharata Drona Parva (Dronabhisheka Parva) Chapter 12:2 If brought hither (alive), vanquished once more at dice, the Pandavas will once more go to the woods, for they are all obedient to Yudhishthira. It is evident that such a victory will be an enduring one. It is for this that I do not, by any means, desire the slaughter of king Yudhishthira the just." Ascertaining this crooked purpose of Duryodhana, Drona who was conversant with the truths of the science of profit and gifted with great intelligence, reflected a little and gave him the boon circumscribing it in the following way. Drona said, "If the heroic Arjuna do not protect Yudhishthira in battle, thou mayst think the eldest Pandava as already brought under thy control. As regards Partha, the very gods and the Asuras together headed by Indra, cannot advance against him in battle. It is for this that I dare not do what thou askest me to do. Without doubt, Arjuna is his disciple, and I was his first preceptor in arms. He is, however, young, endued with great good fortune, and excessively intent (on the achievement of his purposes). He hath obtained, again, many weapons from Indra and Rudra. He hath besides been provoked by thee. I dare not, therefore, do what thou askest me. Let Arjuna be removed, by whatsoever means that can be done, from the battle. Upon Partha being withdrawn, thou mayst regard king Yudhishthira as already vanquished. Upon his seizure is victory and not upon his slaughter, O bull among men! Even by stratagem, can his seizure be accomplished. Seizing that king devoted to truth and righteousness, I will, without doubt, O monarch, bring him to thy control this very day, if he stays before me in battle even for a moment, of course, if Dhananjaya, the son of Kunti, that tiger among men, be withdrawn from the field. In Phalguni's presence, however, O king, Yudhishthira is incapable of being taken in battle even by the gods and the Asuras headed by Indra. Sanjaya continued, 'After Drona had promised the king's seizure even under these limitations, thy foolish sons regarded Yudhishthira as already taken. Thy son (Duryodhana) knew Drona's partiality for the Pandavas. In order to make Drona stick to his promise, therefore, he divulged those counsels. Then, O chastiser of foes, the fact of Drona's having promised to seize the (eldest) Pandava was proclaimed by Duryodhana unto all his troops.