It is narrated from Jabir (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) set out towards Makkah in the year of the conquest of Makkah during Ramadan. He (peace be upon him) kept the fast until he reached the place of "Kura‘ al-Ghamim." The people were also fasting with him. It was said to him (peace be upon him) that fasting had become difficult for the people. After ‘Asr, he (peace be upon him) called for a cup of water, drank it while the people were watching, and some broke their fast while others continued fasting. When he (peace be upon him) was informed that some people were still fasting, he (peace be upon him) said: "They are disobedient."
Hadith Referenceمسند الإمام الشافعي / كتاب الصيام / 621
Hadith Takhrijأخرجه مسلم، الصيام، باب جواز الصوم والفطر في شهر رمضان للمسافر في غير معصية (1114).