Sunan An-Nasa'i

It was narrated that Ibn Al- Hawtakiyyah said:""Umar, May Allah be pleased with us on the day when we stopped at Al-Qaha?' Abu Dharr said: 'I was. A rabbit was brought to the Messenger Allah and the man who brought it said: I saw it bleeding (menstruating). The Prophet did not eat, then he said: ""Eat."" A man said: ""I am fasting."" He said: ""What fast are you observing?"" He said: ""Three days each month"" He said: ""Why don't yo