Raba'i bin Harash bin Jahsh ربعي بن حراش · The Book of Fasting

"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."

"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."

"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."'