Sunan an-Nasa'i, Volume 3, Book 22, Hadith 2347 (DarusSalam) ⓘ
It was narrated that Ibn 'Abbas said: "The Messenger of Allah would not break fast on the days of Al-Bid whether he was a resident or traveling."
أَخْبَرَنَا الْقَاسِمُ بْنُ زَكَرِيَّا، قَالَ حَدَّثَنَا عُبَيْدُ اللَّهِ، قَالَ حَدَّثَنَا يَعْقُوبُ، عَنْ جَعْفَرٍ، عَنْ سَعِيدٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم لاَ يُفْطِرُ أَيَّامَ الْبِيضِ فِي حَضَرٍ وَلاَ سَفَرٍ .
also referenced under: Hadith 2345 (Reference) & Book 22, Hadith 256 (In-Book)