The prohibitions during the month of Ramadan are quite strict. Deliberate eating, drinking, smoking or having sex during the day “devalues” the fast. However, since forgetting cannot be punished, accidentally eating or drinking does not invalidate the fast. Intentionally having sex during Ramadan is considered a “great sin.” It is perfectly permissible to swallow your own saliva and, of course, to brush your teeth. The only thing really forbidden is to swallow anything other than your own saliva. Also forbidden is obscene language, insults, false statements, and even “unkind” behavior. A healthy diet and good hydration are also preferable when breaking the fast.