Is a woman who breaks her fast in Ramadan due to a legitimate Shar'i excuse sinful if she performs cupping (hijamah) on a fasting woman who believes that cupping does not break the fast, based on the saying of the Prophet, peace and blessings be upon him: "The cupper and the cupped person have broken their fast"?

The jurists differed on whether cupping breaks the fast of a fasting person, holding two opinions:

The first: That it breaks the fast of a fasting person. This is the view of the Hanbalis and a group of the Salaf, who cite the Hadith (definition): "The cupper and the one for whom cupping is done have broken their fast."

The second: That it does not break the fast of a fasting person. This is the view of the majority of jurists.

Based on the opinion that cupping breaks the fast, it is not permissible for you to perform cupping on a fasting woman, because that is aiding in a sin (intentional breaking of the fast), unless the cupping is necessary for an illness and cannot be postponed until after breaking the fast. In this case, it is permissible, because it is aiding in a permissible breaking of the fast.