´It was narrated from Ibn 'Umar that the Messenger of Allah mentioned Ramadan and said:` "Do not fast until you see the crescent, and do not stop fasting until you see it, and if it is obscured from you (too cloudy), then work it out."
Hadith ReferenceSunan an-Nasa'i / The Book of Fasting / Hadith: 2123
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:متفق عليه