"大疫不过三" (dà yì bù guò sān) is a Chinese saying that means "a major epidemic will not last more than three years." This saying is bepeved to come from the Yellow Emperor's Inner Canon, a Chinese medical text that is over 2,000 years old.

Here are some examples of how this saying could be used in Engpsh, along with their translations:

"I know things seem really bad right now with the pandemic, but remember, '大疫不过三' - it will pass eventually." (我知道现在疫情看起来很糟，但是记住，“大疫不过三”——它终究会过去的。)
"I try to remind myself that this crisis won't last forever - after all, '大疫不过三.' " (我努力提醒自己，这场危机不会永远持续下去——毕竟，“大疫不过三”。)