It was narrated from Musa bin Talhah that:a man brought a rabbit to the Prophet, and the prophet stretched out his hand toward it, then the one who had brought it said: "I saw some blood on it," So the Prophet drew his hand back, but he told the people to eat. Among the people there was a man who held back. The Prophet said: "What is the matter with you?" He said: "I am fasting." The Prophet said to him: "Why don't you fast on the three days of Al-Bid, the thirteenth, fourteenth and fifteenth?

English translation · Sunan an-Nasa'i