In Jain tradition, Diwali is observed as the day Mahavira attained nirvana (moksha). Most accounts say that Mahavira delivered his final teachings to his sangha just before moksha and then left the earthly body. However, the exact details—such as the precise place, the wording of the last sermon, and the sequence—vary somewhat between Digambar and Shwetambar sources.

• Digambar view: Mahavira’s nirvana is tied to Pavapuri (Vidiśa) and is often linked with his final instructions to his disciples, emphasizing the core Jain path (right faith, right knowledge, right conduct) and the liberation of the soul.
• Shwetambar view: Similar emphasis on his final teachings and the moment of moksha, but with some differences in narrative details and phrasing of the last sermon.

If you’d like, I can summarize the exact verses and their meanings from canonical Jain texts, and note where Digambar and Shwetambar traditions diverge.