Lord Shiva revealed to the sages that a female sex organ was nothing but a symbolic expression of goddess Parvati where as a male sex organ symbolized his own self. He also cautioned them against making fun of hermits appearance. He said- “These hermits who appear absured by their looks are my great devotees. They don’t care about their physical appearance because I predominantly occupy their thoughts. Anybody making fun of these ‘naked’ hermits, whose bodies are smeared with ashes is in fact making fun of me.”
Lord Shiva then went on to describe the purity of ash and said—Ash is extremely pure, as it is the residual element of matter, which is left after burning. It is sacred and indestructible. This is why I smear it on my body. A person who smears ash on his body becomes liberated from all his sins. It is the destroyer of sin. It is the symbolic expression of my veerya (semen). This way Lord Shiva enlightened them on various spiritual topics.