The mother of Saʿd bin 'Ubada died in his absence. He said, "O Messenger of Allah ﷺ! My mother died in my absence; will it be of any benefit for her if I give Sadaqa on her behalf?" The Prophet ﷺ said, "Yes," Saʿd said, "I make you a witness that I gave my garden called Al Makhraf in charity on her behalf."
يَا رَسُولَ اللَّهِ إِنَّ أُمِّي تُوُفِّيَتْ وَأَنَا غَائِبٌ عَنْهَا أَيَنْفَعُهَا شَىْءٌ إِنْ تَصَدَّقْتُ بِهِ عَنْهَا قَالَ نَعَمْ قَالَ فَإِنِّي أُشْهِدُكَ أَنَّ حَائِطِي الْمِخْرَافَ صَدَقَةٌ عَلَيْهَا