One who becomes obligated to fast during the day must abstain and make up the fast; why is abstention required?

Question:
Honorable Shaykh, may Allah grant you success, this matter is confusing to me. One who becomes obligated to fast during the day must abstain and make up the fast. This means the obligation upon him is fasting one day and part of a day. How do we obligate him with this, when the obligation upon him is only to fast one day?

Answer:
The obligation upon him is to fast one day, which is the make-up fast, and to fast the rest of the day for the sake of respecting the time. For the sake of respecting the time. People are fasting and you are eating. Whoever sees you thinks you are being disrespectful; he does not know that you are coming from a journey or something else. So it is better that you abstain, that you abstain with the people so that you are not thought ill of. Also, out of respect for the time. Yes.