Thus strong wind does not last all morning.
Sudden rain does not last all day.
Even Heaven and Earth cannot make it last
Tao Te Ching, Chapter 23
The third cure teaches that evils are easy to endure, and the above Taoist verse specifically teaches the consolation of impermanence. Acute pains are only temporary, and we eventually get used to chronic ones and can focus on other things.
This verse teaches that in all of nature we observe this: nature is too fluid for evils to be everlasting or persistent.