Mentioning the wisdom behind the fasting person who is cupped breaking his fast.

The Shaykh : Is there a cause or wisdom for the fact that the person who is cupped breaks his fast? The answer is yes, because when blood is extracted from the body, it weakens and is unable to complete the fast. So out of Allah’s mercy, he is thereby considered to have broken his fast so that he may consume what strengthens his body. For this reason, we say that cupping is forbidden for one whose fast is obligatory, whereas for one whose fast is voluntary, the person fasting voluntarily may either complete it or break it if he wishes.