question #3 Sahih Muslim 1161d, Book 13, Hadith 259 : What are the implications of having doubts about the number of days to fast as mentioned in the narration?

Did you observe fast in the middle of this month. i. e. Sha’ban? He said: No. Thereupon he said to him: When it is the end of Ramadan, then observe fast for one day or two (Shu’ba had some doubt about it) but he said: I think that he has said: two days.