Muammar (who is a well-known hadith narrator) once asked Sayyiduna Saeed bin Musayyib, may Allah have mercy on him, about the ruling of fasting while traveling. He narrated this hadith to him from Sayyiduna Umar, may Allah be pleased with him, that we participated twice in jihad with the Prophet (peace and blessings be upon him) during the month of Ramadan: once at the Battle of Badr and once at the Conquest of Makkah, and on both occasions we did not fast.