In the Shiva Purana, Shiva becomes associated with ash after he teaches who a lesson?

In the Shiva Purana, Lord Shiva becomes associated with ash after he teaches Lord Brahma a lesson. The story narrates that Brahma became arrogant and claimed supremacy over creation. To humble Brahma and demonstrate the transient nature of the material world, Shiva appeared as a fiery pillar (the Jyotirlinga) and eventually burned Kama (the god of desire) to ashes. Shiva then smeared his body with the sacred ash (vibhuti or bhasma), symbolizing detachment and the impermanence of worldly existence. This act teaches the lesson of renunciation and the futility of pride and ego.