भीष्मपर्व — अध्याय 54: फल्गुन-प्रतिरोधः, सौबली-व्यूह-विध्वंसः, दुर्योधन-भीष्म-संवादः
काशिराज श्च शैब्यश्न रथानामयुतैस्त्रिभि: । राजा विराट केकयराजकुमारोंके साथ उस व्यूहके जघन (कटिके अग्रभाग)-की रक्षा करते थे। काशिराज और शैब्य भी तीस हजार रथियोंके साथ उसीकी रक्षामें तत्पर थे
kāśirājaś ca śaibyaś ca rathānām ayutais tribhiḥ | rājā virāṭaḥ kekayarājakumāraiḥ saha tasya vyūhasya jaghanaṃ (kaṭy-agrabhāgaṃ) rakṣati sma | kāśirājaś ca śaibyaś ca triṃśatsahasrarathibhiḥ saha tasyā rakṣāyāṃ tatparau babhūvatuḥ ||
काशिराजश्च शैब्यश्च रथानामयुतैस्त्रिभिः ।
संजय उवाच
The verse highlights kṣatriya-dharma in practice: leaders and allies must protect assigned sectors of the army formation with steadiness and coordination. Ethical emphasis lies in responsibility, loyalty to one’s role, and disciplined protection of the vulnerable rear.
Sañjaya describes the deployment of forces within a vyūha: Virāṭa and the Kekaya princes guard the rear of the formation, while Kāśirāja and Śaibya support that same rear-guard with large chariot contingents, ensuring the array is not broken from behind.