Sunan an-Nasa'i #3666 · The Book of Wills

Sunan an-Nasa'iIt was narrated from Sa'd bin 'Ubadah that his mother died. He said
Sunan an-Nasa'i · Book 30 · The Book of Wills
Sunan an-Nasa'i · كتاب 30 · كتاب الوصايا
"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
أَخْبَرَنِي إِبْرَاهِيمُ بْنُ الْحَسَنِ، عَنْ حَجَّاجٍ، قَالَ سَمِعْتُ شُعْبَةَ، يُحَدِّثُ عَنْ قَتَادَةَ، قَالَ سَمِعْتُ الْحَسَنَ، يُحَدِّثُ عَنْ سَعْدِ بْنِ عُبَادَةَ، أَنَّ أُمَّهُ، مَاتَتْ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّ أُمِّي مَاتَتْ أَفَأَتَصَدَّقُ عَنْهَا قَالَ ‏
"‏ نَعَمْ ‏"‏‏.‏ قَالَ فَأَىُّ الصَّدَقَةِ أَفْضَلُ قَالَ ‏"‏ سَقْىُ الْمَاءِ ‏"‏‏.‏ فَتِلْكَ سِقَايَةُ سَعْدٍ بِالْمَدِينَةِ‏.‏
Reference : Sunan an-Nasa'i 3666In-book reference : Book 30, Hadith 56