Hadith 4:131
Ghundar narrated to us, from Shu'bah, from Abu al-Fayd, who said: We were on a military expedition and we had a commander over us. He said: "Do not fast, and whoever has fasted, let him break his fast." Abu al-Fayd said: I met Abu Qirṣafah, a man from the companions of the Prophet (peace and blessings of Allah be upon him), and I asked him about that. He said: "If you were to fast, then fast, then fast, you would not make up for it."
حدثنا غندر عن شعبة عن أبي الفيض قال كنا في غزوة فكان علينا امير فقال لا تصومن فمن صام فليفطر قال أبو الفيض فلقيت أبا قرصافة رجلا من اصحاب النبي صلى الله عليه وسلم فسالته عن ذلك فقال لو صمت ثم صمت ثم صمت ما قضيت