ENOfficial
Abu Hurairah reported The Messenger of Allah (ﷺ) as saying When a woman gives something her husband has earned without being commanded by him to do so, she has half his reward.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا الْحَسَنُ بْنُ عَلِيٍّ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، عَنْ هَمَّامِ بْنِ مُنَبِّهٍ، قَالَ سَمِعْتُ أَبَا هُرَيْرَةَ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا أَنْفَقَتِ الْمَرْأَةُ مِنْ كَسْبِ زَوْجِهَا مِنْ غَيْرِ أَمْرِهِ فَلَهَا نِصْفُ أَجْرِهِ " .
sunnah.com