King Yudhishthira himself formed his troops in the array known as Vajra. Thus when the troops were thus formed into battle array, and were stationed in proper ranks.
स्वयं युधिष्ठिरो राजा वज्रं व्यूहमथाकरोत्। तथा व्यूढेष्वनीकेषु यथास्थानमवस्थिताः॥