Amr bin Yahya bin 'Ammara عمرو بن يحيى بن عمارة · The Book of Fasting

"Do you have any food for breakfast?" and we would say no, so he would say: "I am fasting." One day he came to us and we had been given some Hais. He said: "Do you have anything (to eat)?" and we said: "Yes, we have been given some Hais." He said: "I started the day wanting to fast," but then he ate.

"The Messenger of Allah commanded us to fast three days of Al-Bid, the thirteenth, fourteenth and fifteenth."