The Book of Wills
30/9. Chapter:
Mentioning The Different Reports From Sufyan
Sunan an-Nasai
أَخْبَرَنَا أَبُو عَمَّارٍ الْحُسَيْنُ بْنُ حُرَيْثٍ، عَنْ وَكِيعٍ، عَنْ هِشَامٍ، عَنْ قَتَادَةَ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ سَعْدِ بْنِ عُبَادَةَ، قَالَ قُلْتُ يَا رَسُولَ اللَّهِ أَىُّ الصَّدَقَةِ أَفْضَلُ قَالَ " سَقْىُ الْمَاءِ ".
It was narrated that Sa'd bin 'Ubadah said: "I said: 'O Messenger of Allah, what kind of charity is best?' He said: 'Providing drinking water.'"
Reference : Sunan an-Nasa'i 3665In-book reference : Book 30, Hadith 55English translation : Vol. 4, Book 30, Hadith 3695