Mbh 7.157.3a

“Sanjaya continued, ‘While Karna was uttering those words, Kripa, the mighty armed son of Saradwat, smiling the while, addressed the Suta’s son in these words, “Thy speech is fair, O Karna! If words alone could lead to success, then with thee, O son of Radha, as his protector, this bull among the Kurus would be considered to have the amplest measure of protection. Thou boastest much, O Karna, in the presence of the Kuru chief, but thy prowess is seldom witnessed, nor, indeed, any result (of thy boastful speeches). Many a time have we seen thee encounter the sons of Pandu in battle. On every one of those occasions, O Suta’s son, thou hast been vanquished by the Pandavas. While Dhritarashtra’s son was being taken away (as a captive) by the Gandharvas, all the troops fought on that occasion except thy single self, who was the first to fly away. In Virata’s city also, all the Kauravas, united together, including thyself and thy younger brother were vanquished by Partha in battle. Thou art not a match for even one of the sons of Pandu, viz., Phalguna, on the field of battle. How then canst thou venture to vanquish all the sons of Pandu with Krishna at their head? Thou indulgest in too much brag, O Suta’s son! Engage thyself in battle without saying anything. To put forth prowess without indulging in brag is the duty of good men. Ever roaring aloud, O Suta’s son like the dry clouds of autumn, thou showest thyself, O Karna to be without substance. The king, however, does not understand it. Thou roarest, O son of Radha, as long as thou seest not the son of Pritha. These thy roars disappear when thou seest Partha near. Indeed, thou roarest as long as thou art out of the range of Phalguna’s shafts. Those roars of thine disappear when thou art pierced with Partha’s shafts. Kshatriyas evince their eminence by means of their arms; Brahmanas, by means of speech; Arjuna evinces his by means of the bow; but Karna, by the castles he builds in the air.