How many witnesses are required to confirm the sighting of the new moon of Ramadan?
General Chapter
Al-Mughni
Book of Fasting
Primary text
The testimony of two just male witnesses is accepted to commence the fast of Ramadan, which is the position of Umar, Ali, Ibn Umar, Ibn al-Mubarak, and the sound opinion of al-Shafi'i. The evidence is the tradition narrated by Abd al-Rahman ibn Zayd ibn al-Khattab that the Prophet (PBUH) said: "Fast upon seeing it [the moon], and break the fast upon seeing it. If it is obscured from you, complete thirty days, and if two just witnesses testify, then fast and break the fast." This is supported by analogy to the testimony regarding the moon of Shawwal, though the analogy is countered by noting that one case is entering worship while the other is exiting it.
Supporting text
Ahmad preferred two witnesses, stating that if one witness sights it alone and informs the city, the people fast based on his report, as narrated in the Hadith. Uthman ibn Affan held that only the testimony of two is accepted, which is the view of Malik, al-Layth, and Ishaq. Abu Hanifa agrees with requiring two witnesses when the sky is cloudy but requires widespread knowledge (Istifadah) when the sky is clear, arguing it is impossible for one person to see it when many others with sound sight do not.