Al-Kāfi - The Book of Fasting

Chapter: Verifying the Rise of the New Moon and Finding Witnesses for It َّادٌ عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَ٠) قَالَ كَانَ عَلِيٌّ (عَلَيْهِ السَّلاَ٠) يَقُولُ لا أُجِيزُ فِي الْهِلالِ إِلاَّ شَهَادَةَ رَجُلَيْنِ عَدْلَيْنِ. 2.

Hammad has narrated from al-Halabiy who has said the following: “Abu ‘Abd Allah (a.s.), has said that ’Amir al-Mu’minin (a.s.), would say, ‘I do not accept a testimony about seeing the crescent if it is from less than two just witnesses.’” صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (16/229))