Abu al-Fayd said: I was on a military campaign in Syria, and Maslamah bin Abd al-Malik gave a sermon and said: Whoever fasted Ramadan on a journey should make it up. So I asked Abu Qirsafah (may Allah be pleased with him), a man from among the Companions of the Messenger of Allah (peace and blessings be upon him), and he said: "Even if I fasted, then fasted again" — and he counted up to ten — "I would not make it up."
It is narrated from Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) that he said: "The one who fasts on a journey is like the one who does not fast while resident." This is mawquf (a Companion's saying), and its chain is broken (munqati'); it is also narrated as marfu' (from the Prophet), but its chain is da'if (weak).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8166