Does licking the lips moistened with water after moisturizing the lips, or after performing ablution (wudu) or a ritual bath (ghusl), break the fast?

For a fasting person, licking one's moistened lips and swallowing one's saliva does not invalidate the fast, because this moisture is not considered eating or drinking; it is merely swallowing one's own saliva. However, if one expels saliva or phlegm to the outer part of the lips and then intentionally swallows it, this does invalidate the fast, and one must be cautious of it. One must also beware of delving too deeply and meticulously into such matters, as this is a blameworthy form of excessive scrupulousness (takalluf) in Islamic law and may lead to spiritual lethargy, obsessive doubts (waswas), or extremism and rigidity.