Narrated Abu Hurairah: The Prophet ﷺ said: If anyone has himself cupped on the 17th, 19th and 21st it will be a remedy for every disease.
Related hadith on this topic
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
The benefit of these dates is from the unseen matter (amr ghayb).
We cannot provide any justification for it.
It is obligatory to have faith in it.
To observe these dates is recommended (mustahabb), and there is also consensus among the ancient physicians that the second half is better in comparison to the first.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 3861