Sahih Bukhari Volume 5, Book 59, Hadith Number 573.

Narrated By Ubaidullah bin Abdullah bin ‘Utba : Ibn Abbas said, Allah’s Apostle fought the Ghazwa (i.e. battles of Al-Fath during Ramadan.”

Narrated Az-Zuhri: Ibn Al-Musaiyab (also) said the same. Ibn Abbas added, “The Prophet fasted and when he reached Al-Kadid, a place where there is water between Kudaid and ‘Usfan, he broke his fast and did not fast afterwards till the whole month had passed away.