Mbh 8.34.9c

All creatures became frightened, and the three worlds began to tremble. Frightful portents appeared when he was on the point of aiming that shaft. In consequence, however, of the pressure caused by the weight of Soma, Agni, and Vishnu that were in that shaft, as also of the pressure caused by the weight of Brahman and Rudra and the latter's bow, that car seemed to sink. Then Narayana, issuing out of the point of that shaft, assumed the form of a bull and raised that large car. During the time the car had sunk and the foe had began to roar, the illustrious Deity, endued with great might began, from rage, to utter loud shouts, standing, O giver of honours, on the head of his bull and the back of his steeds. At that time the illustrious Rudra was employed in eyeing the Danava city. While in that posture, O best of men, Rudra cut off the teats of the horses and clove the hoofs of the bull. Blessed be thou, from the date the hoofs of all animals of the bovine species came to be cloven. And from that time, O king, horses, afflicted by the mighty Rudra of wonderful deeds, came to be without teats. Then Sarva, having stringed his bow and aimed that shaft with which he had united the Pasupata weapon, waited thinking of the triple city. And O king, as Rudra thus stood, holding his bow, the three cities during that time became united. When the three cities, losing their separate characters became united, tumultuous became the joy of the high-souled gods. Then all the gods, the Siddhas, and the great Rishis, uttered the word Jaya, adoring Maheshwara. The triple city then appeared immediately before that god of unbearable energy, that Deity of fierce and indescribable form, that warrior who was desirous of slaying the Asuras. The illustrious deity, that Lord of the universe, then drawing that celestial bow, sped that shaft which represented the might of the whole universe, at the triple city.