It is narrated from Sayyiduna Usamah bin Umayr al-Hudhali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) used to say: "Fast from whiteness (the break of dawn) to the (next) whiteness."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Abu al-Malih (may Allah have mercy on him) except Salim (may Allah have mercy on him), and no one from Salim (may Allah have mercy on him) except Mufaddal (may Allah have mercy on him); and Abu Qutaybah (may Allah have mercy on him) is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الألف / 2900
Hadith Takhrij«أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 1418، والبزار فى «مسنده» برقم: 2335، والطبراني فى «الكبير» برقم: 504»