Sayyiduna Hamzah bin Amr Aslami (may Allah be pleased with him) narrates: He submitted, "O Messenger of Allah (peace and blessings of Allah be upon him)! I find myself strong enough to fast during travel, so will there be any sin upon me (if I fast)?" The Prophet (peace and blessings of Allah be upon him) said: "It is a concession from Allah Almighty, so whoever avails it, it is good, and whoever prefers to fast, there is no sin upon him." (Imam Ibn Hibban, may Allah have mercy on him, says:): 'Urwah bin Zubair heard this narration from Sayyidah Aisha (may Allah be pleased with her), and Abu Marwah heard this narration from Sayyiduna Hamzah bin Amr (may Allah be pleased with him), so the wording of both is different.