I say:
What Imam Ahmad mentioned is precisely what the two imams, al-Bukhārī and Muslim, agreed upon. For this reason, Muslim omitted the hadith mentioning cupping while fasting and included only the report of cupping while in ihrām.
They offered weak interpretations of the hadiths concerning cupping, such as saying, “The two of them were backbiting,” or, “He broke his fast for another reason.” The best interpretation offered is that mentioned by al-Shāfi‘ī and others: that this ruling was abrogated. They argued that this statement was made in Ramadan, whereas his undergoing cupping while in ihrām occurred later, since that ihrām came after Ramadan.
This, too, is weak. Rather, he—may Allah’s blessings be upon him—entered ihrām for ‘umrah in Dhū al-Qa‘dah of the year 6 AH, the year of al-Hudaybiyah. The following year, he entered ihrām for the make-up ‘umrah in Dhū al-Qa‘dah. On the third occasion, in the year of the Conquest, he entered ihrām from al-Ji‘rānah for ‘umrah in Dhū al-Qa‘dah. In the year 10 AH, he entered ihrām for the Farewell Pilgrimage in Dhū al-Qa‘dah. Thus, it has not been specified on which of these occasions he (peace and blessings be upon him) underwent cupping while in ihrām and fasting.
What supports the view that the ihrām during which he underwent cupping preceded the conquest of Mecca is his statement:
“Both the cupper and the one being cupped have broken their fasts.”
He undoubtedly said this in the year of the Conquest, as stated in the strongest hadith reports. Ahmad narrated through his chain of transmission from Thawbān:
“The Messenger of Allah (peace and blessings be upon him) came upon a man undergoing cupping in Ramadan and said, ‘Both the cupper and the one being cupped have broken their fasts.’”