Sahih Bukhari Volume 3, Book 31, Hadith Number 131.Sahih Bukhari Book 31. Fasting Narated By Abdullah bin Umar : Allah’s Apostle said, “The month (can be) 29 nights (i.e. days), and do not fast till you see the moon, and if the sky is overcast, then complete Sha’ban as thirty days.” Related Previous Post Sahih Bukhari Volume 3, Book 31, Hadith Number 132. Next Post Sahih Bukhari Volume 3, Book 31, Hadith Number 130.