Sunan Ibn Majah, Chapter: The Book of Fasting

that a man from the tribe of Banu Abdul-Ashhal, while (one narrator) Ali bin Muhammad said (he was) a man from the tribe of Banu Abdullah bin Kab, said: "The cavalry of the Messenger of Allah (saw) attacked us, so I came to the Messenger of Allah (saw) while he was eating a meal. He said: 'Come and eat.' I said: 'I am fasting.' He said: 'Sit down and I will tell you about fasting. Allah has relieved the traveler of half of the prayer, and He has relieved the traveler, the pregnant, and the nursing mothers of the duty to fast.' By Allah, the Prophet (saw) said them, both, or one of them, and now I feel so disappointed that I had not eaten of the food of the Messenger of Allah (saw)." Hasan