“When her husband is present, no woman should fast any day apart from the month of Ramadan without his permission.” (Using translation from Ibn Mājah 1761)
عَنِ النَّبِيِّ ﷺ قَالَ «لَا تَصُومُ الْمَرْأَةُ يَوْمًا تَطَوُّعًا فِي غَيْرِ رَمَضَانَ وَزَوْجُهَا شَاهِدٌ إِلَّا بِإِذْنِهِ»