Aisha reported: A man came to the Prophet, peace and blessings be upon him, and he said, “O Messenger of Allah, my mother died suddenly without writing a will. I think if she could speak, she would give in charity. Will she have a reward if I give charity on her behalf?” The Prophet said, “Yes.”
Source: Ṣaḥīḥ al-Bukhārī 1388, Ṣaḥīḥ Muslim 1004
Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim
عَنْ عَائِشَةَ أَنَّ رَجُلًا أَتَى النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّ أُمِّيَ افْتُلِتَتْ نَفْسَهَا وَلَمْ تُوصِ وَأَظُنُّهَا لَوْ تَكَلَّمَتْ تَصَدَّقَتْ أَفَلَهَا أَجْرٌ إِنْ تَصَدَّقْتُ عَنْهَا قَالَ نَعَمْ
1388 صحيح البخاري كتاب الجنائز باب موت الفجأة البغتة
1004 صحيح مسلم كتاب الزكاة باب وصول ثواب الصدقة عن الميت إليه