´It was narrated from Shubah:` "Al-Hakam said to me: 'I heard it from him forty years age; Then Al-Hakam said: 'And Maimum bin Abi Shabib narrated it to me from Muadh bin Jabal." (Sahih
Hadith ReferenceSunan an-Nasa'i / The Book of Fasting / Hadith: 2229