Abdullah bin Abbas (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) set out on a journey in the month of Ramadan and fasted until he reached al-Kadid, and then he broke the fast; and the proof is taken from his last action.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8173
Abdullah bin Wahb (may Allah have mercy on him) narrated from Yunus (may Allah have mercy on him) that Ibn Shihab (may Allah have mercy on him) narrated a similar hadith.
Ibn Shihab (may Allah have mercy on him) said: They used to follow the most recent, then the next most recent, of his commands, and they regarded it as the abrogating and decisive ruling.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8174
Sayyiduna Jabir (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) set out in Ramadan in the year of the Conquest of Makkah until he reached Kura' al-Ghamim. We also fasted with him (peace and blessings be upon him), and the fasting became hard on the people, and they were waiting to see what ruling would now come down. So he (peace and blessings be upon him) called for a cup of water after the Asr prayer and drank it while the people were watching. Then the people also broke their fast, but some did not. This reached the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said: "These are the disobedient ones." He said it twice.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8175
Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that food was brought to the Prophet (peace and blessings be upon him) while he (peace and blessings be upon him) was at Marr al-Zahran, and he (peace and blessings be upon him) said to Abu Bakr and Umar (may Allah be pleased with them both): "Eat." They said: We are fasting. So he (peace and blessings be upon him) said: "Saddle up for your two companions and work for your two companions; come close and eat."
Abu Dawud al-Hafari alone narrated it from Sufyan.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8176
Abu al-Bakhtari (may Allah have mercy on him) says that Ubaydah (may Allah have mercy on him) said: When a man sets out on a journey having already fasted part of Ramadan, let him fast the rest; and he recited this verse: "So whoever of you witnesses the month, let him fast it." [Surah al-Baqarah: 185]
Abu al-Bakhtari narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both), and he had more understanding than us: "Whoever wishes may fast, and whoever wishes may break the fast."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8177