Mbh 7.1.6c

Even thus was he classed during the counting of Rathas and Atirathas, he that is the foremost (of all Rathas and Atirathas), he that is respected by all heroes, he that would venture to fight even with Yama, Kuvera, Varuna, and Indra. Through anger caused by this, O king, he had said unto Ganga’s son these words: “As long as thou livest, O thou of Kuru’s race, I will never fight! if thou, however, succeedest in slaying the sons of Pandu in great battle, I shall, O Kaurava, with Duryodhana’s permission, retire into the woods. If, on the other hand, thou, O Bhishma, slain by the Pandavas, attainest to heaven, I shall then, on a single car, slay all of them, whom thou regardest as great car-warriors.” Having said this, mighty-armed Karna of great fame, with thy son’s approval, did not fight for the first ten days. Bhishma, of great prowess in battle and of immeasurable might, slew, O Bharata, a very large number of warriors belonging to Yudhishthira’s army. When, however, that hero of sure aim and great energy was slain, thy sons thought of Karna, like persons desirous of crossing a river thinking of a boat. Thy warriors and thy sons, together with all the kings, cried out, saying, Karna! And they all said, “Even this is the time for the display of his prowess.” Our hearts are turned to that Karna who derived his knowledge of weapons from Jamadagni’s son, and whose prowess is incapable of being resisted! He, indeed, O king, is competent to save us from great dangers, like Govinda always saving the celestials from great dangers.’”