I say, and with God's success: Cupping is most beneficial on the seventeenth, nineteenth, and twenty-first days of the lunar month, as the Prophet (peace be upon him) advised. In Sunan Abu Dawood (4: 3), from the hadith of Abu Huraira (may Allah be pleased with him), he said: The Messenger of Allah (peace be upon him) said: "Cupping on the seventeenth, nineteenth, and twenty-first days is a cure for every disease." Al-Hakim stated in Al-Mustadrak: It meets the criteria of Bukhari and Muslim, but they did not narrate it. It is also established in Tirmidhi (4: 391) from Ibn Mas'ud, who said: The Messenger of Allah (peace be upon him) said: "The best days for cupping are the seventh, nineteenth, and twenty-first." Tirmidhi said: This hadith is good. Al-Bayhaqi (3: 200) narrated other hadiths regarding the times for cupping, so refer to them.