This verse comes from the "Atma Shatakam" or "Nirvana Shatakam," a six-stanza poem written by Adi Shankaracharya. The poem articulates the spiritual journey towards realizing one's own true nature, which is identified with the ultimate reality or Brahman. Each stanza ends with the refrain, "I am Shiva," indicating the identification of the self with the universal consciousness.