Narrated Ibn `Umar: The Prophet said, "The month is like this and this," (at the same time he showed the fingers of both his hands thrice) and left out one thumb on the third time.
Hadith ReferenceSahih Bukhari / The Book of As-Saum (The Fasting). / Hadith: 1908
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة