PURPORT

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.