What is the ruling regarding water that enters the mouth during washing the face for ablution (Wudu')?

A fasting person is required to preserve the soundness of their fast. The mere entry of water into the fasting person's mouth does not harm their fast, as long as it does not reach the throat or the stomach. If water reaches the throat or the stomach due to overwhelming circumstances or forgetfulness, there is no consequence. However, if it is done intentionally, it entails sin and requires making up the fast.