O Karna, O charioteer's son, you boast too much (of your prowess). Be engaged in fight. It is the duty of good (i.e. really brave) men to display their prowess without uttering (a single boastful word).
अब्रुवन् कर्ण युध्यस्व कत्थसे बहु सूतज। अनुक्त्वा विक्रमेद् यस्तु तद् वै सत्पुरुषव्रतम्॥