Musnad Ahmad 1166:7

Abu Dawud al-Tayalisi narrated to us, he said: Shu'bah narrated to us, from Ja'dah, from Umm Hani, that the Messenger of Allah (peace and blessings of Allah be upon him) entered upon her, and he asked for a drink, so he drank, then he handed it to her and she drank. She said: "O Messenger of Allah, I was fasting." The Messenger of Allah (peace and blessings of Allah be upon him) said: "The voluntary fasting person is the master of himself; if he wishes he may fast, and if he wishes he may break his fast." He [the narrator] said: I said to him [Shu'bah]: "Did you hear it yourself from Umm Hani?" He said: "No, Abu Salih and our family narrated it to me from Umm Hani." Sulayman narrated to us, he said: Shu'bah narrated to us, he said: I used to hear Simak saying: "The two sons of Umm Hani narrated to me," so I went to the better and more virtuous of the two, and I asked him, and he was called Ja'dah.