Hadith 4:637
Waki' narrated to us, from Sufyan, from Simak, from Ikrimah, who said: Whoever fasts the day about which there is doubt has disobeyed the Messenger of Allah, may Allah bless him and grant him peace.
حدثنا وكيع عن سفيان عن سماك عن عكرمة قال من صام اليوم الذي يشك فيه فقد عصى رسول الله صلى الله عليه وسلم