This is what I have heard. Once the Blessed One was staying in the Bhagga country at Sumsumaragira, in the Bheskala grove in the animal park. Now the householder Nakulapiter approached the Blessed One. Having approached, he sat down to one side.

Once seated, he said to the Blessed One: “Sir, I am old, getting on, of a venerable age, and experienced in life. Having reached a great age, I am sick in body and frequently ill. So I cannot always get to see the Blessed One or revered monks. Sir, could the Blessed One please direct me, please instruct me, as this would contribute to my welfare and happiness for a long time to come?”

“This is the way it is, householder. This is the way it is. Your body is sick, oppressed, and afflicted. For how could anyone carrying around this body claim freedom from disease for even a second, unless, that is, he was being childish? Therefore, you should practice so that although your body is sick your mind will not be sick. This is how you should practice.”

From Sayings of the Buddha: A Selection of Suttas from the Pali Nikayas, translated by Rupert Gethin, Oxford: Oxford University Press, 2008, p. 216.