Mahabharata Drona Parva Chapter 182:2

Mahabharata Drona Parva (Ghatotkacha-badha Parva) Chapter 182:2 Dhritarashtra said, 'My son is fond of quarrel. His advisers are foolish. He is vain of his wisdom. It is for that, that this certain means of Arjuna's death hath been baffled. Why, O Suta, did not Duryodhana, or that foremost of all wielders, viz., Karna, possessed of great intelligence, hurl that fatal dart at Dhananjaya? Why, O son of Gavalgana, didst thou too forget this great object, possessed as thou art of great wisdom, or why didst not thou remind Karna of it? Sanjaya said, 'Indeed, O king, every night this formed the subject of deliberation with Duryodhana and Sakuni and myself and Duhsasana. And we said unto Karna, "Excluding all other warriors, O Karna, slay Dhananjaya. We would then lord it over the Pandu's and the Panchalas as if these were our slaves. Or, if upon Partha's fall, he of Vrishni's race appoints another amongst the sons of Pandu (in this place for carrying on the fight), let Krishna himself be slain. Krishna is the root of the Pandavas, and Partha is like their risen trunk. The other sons of Pritha are like their branches, while the Panchalas may be called their leaves. The Pandavas have Krishna for their refuge, Krishna for their might, Krishna for their leader. Indeed, Krishna is their central support even as the moon is of the constellations. Therefore, O Suta's son, avoiding the leaves and branches and trunk, slay that Krishna who is everywhere and always the root of the Pandavas. Indeed, if Karna had slain him of Dasarha's race, viz., that delighter of the Yadavas, the whole earth, O king, would, without doubt, have come under thy control. Truly, O monarch, if that illustrious one, that delighter of both the Yadavas and the Pandavas, could be made to lie down on the earth, deprived of life, then certainly, O monarch, the entire earth with the mountains and forests would have owned thy supremacy." We rose every morning, having formed such a resolution in respect of that Lord of the very gods, viz., Hrishikesa of immeasurable energy. At the time of battle, however, we forget our resolution. Kesava always protected Arjuna, the son of Kunti. He never placed Arjuna before the Suta's son in battle.