"O Messenger of Allah, my mother has died; can I give charity on her behalf?" He said: "Yes." He said: "What kind of charity is best?" He said: "Providing drinking water." And that is the drinking-fountain of Sa'd in Al-Madinah. (Using translation from Nasāʾī 3666)
يَا رَسُولَ اللهِ إِنَّ أُمِّي مَاتَتْ أَفَأَتَصَدَّقُ عَنْهَا؟ قَالَ «نَعَمْ» قَالَ فَأَيُّ الصَّدَقَةِ أَفْضَلُ؟ قَالَ «سَقْيُ الْمَاءِ» فَتِلْكَ سِقَايَةُ سَعْدٍ بِالْمَدِينَةِ