In this videoconference talk from 30 November 2018, Ajahn Anan discusses the stories of two monks from the Buddha's time who dealt with different sicknesses but both succeeded in their practice in the end.

An excerpt: "Though his body wasn't strong and his health was no good, but with his wisdom and intelligence, he could listen and receive the Dhamma of the Buddha, and could have knowing and clear seeing arise instantly. He could overcome his mental defilements, and there was no need to be born again into samsara, this round of birth and death and suffering, again. Can you see that wisdom and intelligence is important to fully cut off the mental defilements."

Note: One can read Dhamma talk transcripts at the Wat Marp Jan 'Reflections' page. These include questions and answers with Ajahn Anan, which are not in the audio files. This talk's transcript can be found here: https://watmarpjan.org/en/two-sick-monks/