Does a fasting person break their fast if they lick their lips that are wet with water and then swallow their saliva, and is there any sin in that?

A fasting person licking their lips, if there is moisture on them, and then swallowing their saliva, does not break the fast because of the insignificance of that moisture. It is neither a drink nor food. In doing so, the fasting person is like one who merely swallows their own saliva, and swallowing saliva does not break the fast. The remaining moisture after washing or ablution has no effect on the fast.