Sunan an-Nasa'i, Book 22, Hadith 197 (In-Book) ⓘ
It was narrated from Humaid bin 'Abdur-Rahman bin 'Awf that his father said: "The one who fasts while traveling is like one who does not fast while a resident.' (Daif)
أَخْبَرَنِي مُحَمَّدُ بْنُ يَحْيَى بْنِ أَيُّوبَ، قَالَ حَدَّثَنَا أَبُو مُعَاوِيَةَ، قَالَ حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، عَنِ الزُّهْرِيِّ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ، عَنْ أَبِيهِ، قَالَ الصَّائِمُ فِي السَّفَرِ كَالْمُفْطِرِ فِي الْحَضَرِ .
also referenced under: Hadith 2286 (Reference) & Volume 3, Book 22, Hadith 2288 (DarusSalam)