Majma al-Zawaid — Hadith 10233

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: Then the Prophet (peace and blessings be upon him) set out on his journey. He appointed Sayyiduna Abu Ruhm Kulthum bin al-Husayn bin Utbah bin Khalaf al-Ghifari as his deputy in Madinah. He set out after ten days of Ramadan had passed. The Prophet (peace and blessings be upon him) was fasting, and the people with him were fasting too, until, when he reached a spring of water called al-Kadid between Usfan and Amaj, he broke the fast. Then he kept going until he encamped at Marr al-Zahran; at that time there were ten thousand Muslims with him. (Allamah al-Haythami says:) I say: in the "Sahih" a part of this report is mentioned in the chapter on fasting.
Ahmad recorded it, and its narrators are the narrators of the Sahih except for Ibn Ishaq, and he has explicitly stated that he heard it directly.