Mishkat al-Masabih 6 Zakat كتاب الزكاة 175

وَعَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: أَنَّ رَجُلًا قَالَ لِلنَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: إِنَّ أُمِّي افْتُلِتَتْ نَفْسَهَا وَأَظُنُّهَا لَوْ تَكَلَّمَتْ تَصَدَّقَتْ فَهَلْ لَهَا أَجْرٌ إِنْ تَصَدَّقت عَنْهَا؟ قَالَ: نعم ”

‘A’isha said that a man told the Prophet his mother had died suddenly adding that he thought she would have given sadaqa if she had been able to speak. He therefore asked if she would have a reward supposing he gave sadaqa on her behalf, and was told that she would. (Bukhari and Muslim.)