Sahih Muslim 1024 c
'A'isha reported Allah's Messenger (ﷺ) as saying:
When a woman spends (something as Sadaqa) out of the household of her husband without causing any damage, there is a reward for her and for him too like it for whatever he earned, and for her (for the wife) because of her spending (for the sake of Allah), and for the trustee also (there is a reward like it), without any reduction from their rewards.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ شَقِيقٍ، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ إِذَا أَنْفَقَتِ الْمَرْأَةُ مِنْ بَيْتِ زَوْجِهَا غَيْرَ مُفْسِدَةٍ كَانَ لَهَا أَجْرُهَا وَلَهُ مِثْلُهُ بِمَا اكْتَسَبَ وَلَهَا بِمَا أَنْفَقَتْ وَلِلْخَازِنِ مِثْلُ ذَلِكَ مِنْ غَيْرِ أَنْ يَنْتَقِصَ مِنْ أُجُورِهِمْ شَيْئًا ‏"‏ ‏.‏