I said, "Messenger of Allah, my mother has died. Should I give charity on her behalf?"He replied, "Yes."I asked, "Which charity is best?"He answered, "Providing water."
أخبرنا محمد بن عبد الله بن المبارك قال حدثنا وكيع عن هشام عن قتادة عن سعيد بن المسيب
قلت يا رسول الله إن أمي ماتت أفأتصدق عنها قال نعم قلت فأي الصدقة أفضل قال سقي الماء
[Its chain of transmission is daif]Ibn Majah reported it in the Book of Manners, Chapter on the Merit of Giving Water in Charity, hadith 3684, from the hadith of Waki, through this same chain. It also appears in al-Kubra, hadith 6491. Ibn Hibban graded it sahih, hadith 858, and Hakim said it met the criteria of the two Shaykhs, 1/414, but Dhahabi rejected this, saying, "No, it is not connected," meaning that Saeed bin Musayab did not meet Saad bin Ubada. Part of the hadith has a supporting narration mentioned earlier, hadith 3680.Hisham here is Dastawai.