Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
ahmad:22458 – Hāshim > al-Mubārak > al-Ḥasan > Saʿd b. ʿUbādah

[Machine] The Messenger of Allah ﷺ passed by me, so I said, "O Messenger of Allah, guide me to a charity." He said, "Give water to drink."  

أحمد:٢٢٤٥٨ – حَدَّثَنَا هَاشِمٌ أَخْبَرَنَا الْمُبَارَكُ عَنِ الْحَسَنِ عَنْ سَعْدِ بْنِ عُبَادَةَ قَالَ

مَرَّ بِي رَسُولُ اللهِ ﷺ فَقُلْتُ يَا رَسُولَ اللهِ دُلَّنِي عَلَى صَدَقَةٍ قَالَ اسْقِ الْمَاءَ  

See similar narrations below:

Collected by Ṭabarānī
tabarani:5384 – Abū Yazīd al-Qarāṭīsī > Asad b. Mūsá > Mubārak b. Faḍālah > al-Ḥasan > Saʿd b. ʿUbādah

"I said: 'O Messenger of Allah, what charity is best?' He said: 'Giving water to drink.'" (Using translation from Ibn Mājah 3684)   

الطبراني:٥٣٨٤ – حَدَّثَنَا أَبُو يَزِيدَ الْقَرَاطِيسِيُّ ثنا أَسَدُ بْنُ مُوسَى ثنا مُبَارَكُ بْنُ فَضَالَةَ عَنِ الْحَسَنِ عَنْ سَعْدِ بْنِ عُبَادَةَ قَالَ

قُلْتُ يَا رَسُولَ اللهِ دُلَّنِي عَلَى صَدَقَةٍ قَالَ «اسْقِ الْمَاءَ»