References – SN 55.22: With Mahānāma (2nd) 
“I am concerned about the clarity of mind if I have prolonged pain. How does one face death skillfully if one is in constant serious pain?” Answered by Ajahn Pasanno and Ajahn Karuṇadhammo. [Pain] [Ageing] [Tranquility] [Death] // [Long-term practice]
Sutta: SN 55.22: Mahānāma worries about death. [Similes]
28th Anniversary Practice and Study Day [2024], Session 4, Excerpt 2