It differs from fainting in that regard.

513 - Issue: He said: (And if one sees the new crescent moon of the month of Ramadan alone, he must fast).

The famous opinion in the school of thought is that whenever a single person sees the crescent moon, fasting becomes mandatory for him, whether he is a person of integrity or otherwise, whether he testified before the judge or did not, and whether his testimony was accepted or rejected. This is the opinion of Malik, Al-Layth, Al-Shafi'i, the People of Opinion, and Ibn al-Mundhir. 'Ata' and Ishaq said: He should not fast. Hanbal narrated from Ahmad that he said: He does not fast unless it is with the congregation of people. A similar report was narrated from Al-Hasan and Ibn Sirin; because it is a day deemed to be from Sha'ban, so it resembles the twenty-ninth day. Our evidence is that he attained certainty that it is from Ramadan, so fasting it becomes mandatory for him, just as if the judge had ruled it to be so. His being deemed to be from Sha'ban is apparent regarding others, but inwardly he knows that it is from Ramadan, so fasting it becomes mandatory for him, just like the person of integrity.

Section: If he breaks his fast on that day by having intercourse, then the expiation (kaffarah) is mandatory upon him. Abu Hanifa said: It is not mandatory; because it is a punishment, and it is not mandated by an act that is subject to difference of opinion, like the legal penalty (hadd). Our evidence is that he broke the fast of a day of Ramadan by intercourse, so the expiation became mandatory for him, just as if his testimony had been accepted. We do not concede that the expiation is a punishment. Furthermore, their analogy is invalidated by the necessity of the expiation during a short journey, despite the existence of disagreement regarding it.

514 - Issue: He said: (And if he is a person of integrity, people shall be made to fast based on his statement).

The famous opinion from Ahmad is that the statement of one person of integrity is accepted regarding the crescent of Ramadan, and fasting becomes mandatory for the people based on his statement. This is the opinion of Umar, Ali, Ibn Umar, Ibn al-Mubarak, and Al-Shafi'i in his...