The five mantras
Five is a sacred number for Shiva. One of his most important mantras has five syllables (namaḥ śivāya).Shiva's body is said to consist of five mantras, called the pañcabrahmans. As forms of God, each of these have their own names and distinct iconography:
These are represented as the five faces of Shiva and are associated in various texts with the five elements, the five senses, the five organs of perception, and the five organs of action. Doctrinal differences and, possibly, errors in transmission, have resulted in some differences between texts in details of how these five forms are linked with various attributes.The overall meaning of these associations is summarized by Stella Kramrisch:
Through these transcendent categories, Śiva, the ultimate reality, becomes the efficient and material cause of all that exists.
According to the Pañcabrahma Upanishad:
One should know all things of the phenomenal world as of a fivefold character, for the reason that the eternal verity of Śiva is of the character of the fivefold Brahman. (Pañcabrahma Upanishad31)