evam dagdhva puras tisro
bhagavan pura-ha nrpa
svam dhama pratyapadyata
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O King Yudhisthira, thus Lord Siva is known as Tripurari, the annihilator of the three dwellings of the demons, because he burnt these dwellings to ashes. Being worshiped by the demigods, headed by Lord Brahma, Lord Siva returned to his own abode.