´It was narrated form Ibn 'Umar that the Prophet said:` "D not fast until you see it , and do not stop fasting until you see it, and if it is obscured from you (too cloudy), then work it out."
Hadith Referenceسنن نسائي / كتاب الصيام / 2124
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:إسناده صحيح
´It was narrated that Abu Hurairah said:` "The Messenger of Allah mentioned the crescent and said: 'When you see it, fast and when you see it, stop fasting, and if it is obscured from you (too cloudy), then count thirty days."'
Hadith Referenceسنن نسائي / كتاب الصيام / 2125
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم