Sunan Ibn Majah, Book 7, Hadith 1833 (In-Book) ⓘ
It was narrated from Abu Hurairah that the Prophet said: “When her husband is present, no woman should fast any day apart from the month of Ramadan without his permission.”
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ ـ صلى الله عليه وسلم ـ قَالَ " لاَ تَصُومُ الْمَرْأَةُ وَزَوْجُهَا شَاهِدٌ يَوْمًا مِنْ غَيْرِ شَهْرِ رَمَضَانَ إِلاَّ بِإِذْنِهِ " .
also referenced under: Hadith 1761 (Reference) & Volume 2, Book 7, Hadith 1761 (DarusSalam)