If sleep overtakes a person before confirming the intention to fast, and mucus is later swallowed due to habit or difficulty breathing, how is the validity of the fast viewed, What is the ruling on making up a missed fast (qadaa’) in this situation?

If you hesitate in the intention to fast a wajib (obligatory) make-up fast, your fast is not valid, due to the saying of the Prophet, peace be upon him: "Indeed, actions are by intentions," and because a firm intention is a condition for its validity. If you do not form the intention from the night, the obligatory fast is not valid. However, your fast on that day can be valid as a supererogatory fast, as it is permissible to form its intention during the day. As for swallowing mucus, it does not invalidate the fast if it does not reach the mouth. If it does reach the mouth, there is a difference of opinion among the jurists.