In the Aggi-Vacchagotta Sutta (MN 72), the wanderer Vacchagotta questions the Buddha on various metaphysical topics, including the nature of the cosmos and the existence of the Tathāgata (the Buddha) after death. The Buddha refrains from engaging in speculative views, describing them as a "thicket of views" that lead to suffering and do not contribute to enlightenment.

To elucidate his perspective, the Buddha employs the analogy of an extinguished fire. He explains that just as a fire, dependent on fuel, ceases without direction when the fuel is exhausted, similarly, a Tathāgata, having relinquished all attachments and identifications with the five aggregates (form, feeling, perception, fabrications, and consciousness), becomes "deep, immeasurable, hard to fathom, like the sea." Consequently, concepts like "reappears" or "does not reappear" do not apply to an enlightened being after death.

https://suttacentral.net/mn72/en/sujato?lang=en