Sunan an-Nasa'i #3664 · The Book of Wills

Sunan an-Nasa'iIt was narrated that Sa'd bin 'Ubadah said
Sunan an-Nasa'i · Book 30 · The Book of Wills
Sunan an-Nasa'i · كتاب 30 · كتاب الوصايا
"I said: 'O Messenger of Allah, my mother has died; shall I give in charity on her behalf?' He said: 'Yes.' I said: 'What kind of charity is best?' He said: 'Providing drinking water
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ الْمُبَارَكِ، قَالَ حَدَّثَنَا وَكِيعٌ، عَنْ هِشَامٍ، عَنْ قَتَادَةَ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ سَعْدِ بْنِ عُبَادَةَ، قَالَ قُلْتُ يَا رَسُولَ اللَّهِ إِنَّ أُمِّي مَاتَتْ أَفَأَتَصَدَّقُ عَنْهَا قَالَ ‏
"‏ نَعَمْ ‏"‏‏.‏ قُلْتُ فَأَىُّ الصَّدَقَةِ أَفْضَلُ قَالَ ‏"‏ سَقْىُ الْمَاءِ ‏"‏‏.‏
Reference : Sunan an-Nasa'i 3664In-book reference : Book 30, Hadith 54