SB 8.7.21
sri-prajapataya ucuh
deva-deva maha-deva
bhutatman bhuta-bhavana
trahi nah saranapannams
trailokya-dahanad visat
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The prajapatis said: O greatest of all demigods, Mahadeva, Supersoul of all living entities and cause of their happiness and prosperity, we have come to the shelter of your lotus feet. Now please save us from this fiery poison, which is spreading all over the three worlds.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Since Lord Siva is in charge of annihilation, why should he be approached for protection, which is given by Lord Visnu? Lord Brahma creates, and Lord Siva annihilates, but both Lord Brahma and Lord Siva are incarnations of Lord Visnu and are known as saktyavesa-avataras. They are endowed with a special power like that of Lord Visnu, who is actually all-pervading in their activities. Therefore whenever prayers for protection are offered to Lord Siva, actually Lord Visnu is indicated, for otherwise Lord Siva is meant for destruction. Lord Siva is one of the isvaras, or the controllers known as saktyavesa-avataras. Therefore he can be addressed as having the qualities of Lord Visnu.