´It was narrated that Ibn Abbas said:` "The Messenger of Allah said; 'Fast when you see it and stop fasting when you see it, and if it is obscured from you (too cloudy), then complete thirty (days)."'
Hadith Referenceسنن نسائي / كتاب الصيام / 2126
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:إسناده صحيح
´It was narrated that Ibn 'Abbas said:` " I am surprised at those who anticipate the moth, when the Messenger of Allah said: 'When you see the new crescent then fast, and when you see it, then stop fasting, and if it is obscured from you (too cloudy), then complete thirty days.