Inside the mouth, in terms of wudu', is deemed an inner limb, but it is considered an external limb when one is in a state of fasting. That is the reason why the blood issuing from a tooth or a wound inside the mouth while remaining in the mouth does not break wudu'. But after coming out of the mouth, it breaks wudu' if the blood predominates over the saliva. (Halabi) In some cases the mouth is thought of as an internal part of the body. Hence, if a fasting person swallows his saliva, his fast will not break. It is like something dirty inside the body passing from stomach to intestines. Bleeding from an injury in the mouth or blood coming from the stomach to the mouth doesn’t break one's fast or wudu'. When one spits out or swallows this blood, if the quantity of the saliva is greater than the blood, that is, if it is yellow in color, they are still not broken. It is the same when other things come to the mouth from the stomach, in which case neither the wudu' nor the fast is broken. If a mouthful (comes to the mouth and) goes out of the mouth, both are broken. The inside of the mouth is sometimes considered to be an outer part of the body. The fast is not broken when water is taken into the mouth. (Bahr-ur-raiq, Jawhara) This means that the fast is not broken if the blood in the mouth is spat. The wudu' is not broken if it is swallowed. If blood is swallowed, the fast is broken. If it is spat, then the wudu' is broken.