The Messenger of Allah ﷺ said, "Allah loves that His concessions be accepted, just as He hates that His disobedience be committed."
قال رسول الله ﷺ: إن الله يحب أن تؤتى رخصه كما يكره أن تؤتى معصيته.
Imam Ahmad narrated it (5873), and Bazzar in Kashf Astar (988), and Ibn Khuzayma graded it sahih (950), and Ibn Hibban (2742), all of them from the hadith of Umara bin Ghaziya, from Harb bin Qays, from Nafi, from Ibn Umar, who mentioned it. Its isnad is hasan because of Harb bin Qays, for he is hasan al-hadith. It has fallen out of some hadith sources, but the correct approach is to mention it.On this subject there is also a report from Ammar bin Yasir, who said, We came with the Messenger of Allah ﷺ from a military expedition, and we traveled on a day of intense heat. We stopped along the way, and a man among us went off and took shelter under a tree. His companions gathered around him, and he was lying down as if in pain. When the Messenger of Allah ﷺ saw them, he said, "What is wrong with your companion?" They said, "He is fasting." The Messenger of Allah ﷺ said, "It is not righteousness to fast while traveling. Take the concession that Allah has granted and accept it."Tabarani narrated it from the hadith of Ibn Lahia, who said, Qurra and Aqeel told me, from Ibn Shihab, from Saeed, from Ammar, who mentioned it. This is how Ibn Kathir mentioned it in Jami al-Masanid (6869). The Musnad of Ammar has not been printed, so I was not able to identify the name of the narrator from Ibn Lahia. Munziri mentioned it in Targheeb wa Tarheeb (1624) and said, "Its isnad is hasan." Haythami followed him in Majma (3/161) and said, "Tabarani narrated it in Kabir, and its isnad is hasan."On this subject there is also what was reported from Abu Barza as a raised hadith, "It is not righteousness to fast while traveling." Bazzar narrated it in Kashf Astar (987) from Muhammad bin Muamar, who said, Muhammad bin Khalid bin Uthma told us, Ibrahim bin Saad told us, Abdullah bin Amir told us, from Muhammad, from a man from the family of Abu Barza, from Abu Barza, who mentioned it. It contains an unnamed man, and Haythami also pointed to this in Majma (3/161), and he also attributed it to Ahmad and to Tabarani in Kabir. As for the Musnad of Imam Ahmad, I did not find it there. As for Tabarani, he narrated it in Awsat (5593) from Muhammad bin Abdullah Hadrami, who said, Muamar bin Bakkar Saadi told us, who said, Ibrahim bin Saad told us, from Abdullah bin Amir Aslami, from his maternal uncle Abdul-Rahman bin Harmala, from Muhammad bin Munkadir, from Abu Barza, who mentioned it.Tabarani said, "No one has narrated this hadith from Abdul-Rahman bin Harmala except Abdullah bin Amir, and no one has narrated it from Abdullah bin Amir except Ibrahim bin Saad. Muamar bin Bakkar narrated it alone, and it is not narrated from Abu Barza except by this isnad." I say, Muamar bin Bakkar Saadi is a subject of disagreement. Ibn Hibban mentioned him in Thiqat, and Dhahabi said in Mizan (4/153), "Fairly sound." But Aqeeli said in Dhahabi's Duafa (1792), "There is confusion in his hadith, and he is not corroborated in most of it." Perhaps this is one such case, for there is disorder in the isnad, as you can see.The summary regarding the fasting of the traveler, as issued in the fatwa of the Permanent Committee, is, "It is permissible for a traveler on a journey of the distance that permits shortening prayers to break his fast during his journey, whether he is walking or riding, and whether his riding is by car, airplane, or otherwise, and whether he becomes so tired during his journey that he cannot bear fasting or is not tired, whether hunger or thirst afflicts him or none of that befalls him. This is because the Sharia granted the concession unconditionally to a traveler on such a journey to break the fast, and to shorten the prayer, and similar travel concessions, without restricting that to any particular type of transport, nor to the fear of fatigue, hunger, or thirst. The companions of the Messenger of Allah ﷺ used to travel with him on military expeditions during the month of Ramadan, and some of them would fast while others would break their fast, and neither group found fault with the other. However, it is strongly recommended for the traveler to break his fast in the month of Ramadan if fasting becomes difficult for him, due to intense heat, rugged terrain, great distance, continuous travel, or similar circumstances." End of quote.