niriksya prtanam devah
parair abhyarditam rane
udayacchad ripum hantum
vajram vajra-dharo rusa
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When Indra, who is known as Vajra-dhara, the carrier of the thunderbolt, saw his own soldiers so oppressed by the enemies on the battlefield, he became very angry. Thus he took up his thunderbolt to kill the enemies.