It is narrated from Sayyiduna Kudayr al-Dabbi (may Allah be pleased with him) that a man came to the Messenger of Allah (peace and blessings be upon him) and said: "O Messenger of Allah! Tell me of a deed that will admit me into Paradise." He (peace and blessings be upon him) said: "Speak what is just and fair, and give away the surplus of your wealth (in the way of Allah)." He said: "And if I am unable to do that?" He (peace and blessings be upon him) said: "Then feed (the hungry) and spread the greeting of peace (salam)." He said: "And if I am unable or do not have the capacity for that either?" He (peace and blessings be upon him) asked: "Do you have any camels?" He said: "Yes." He (peace and blessings be upon him) said: "Then take one (strong) camel from your camels and a waterskin, and look for a household that gets water only every other day (due to its scarcity), and give them water to drink; for it is quite possible that your camel will not perish nor your waterskin tear before Paradise becomes binding for you (through the blessing of this great deed)."
Abu Dawud al-Tayalisi recorded this hadith in his Musnad, and in its chain Shu'bah has explicitly stated that he heard directly from his teachers. This report is of hasan grade, and it describes the great virtue of giving water to the needy and serving people.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الأطعمة والأشربة / 2436
Hadith Gradingمحدثین:إسناده ضعيف، مرسل
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :مرسل، إسناده ضعيف. » «أخرجه مجمع الزوائد ومنبع الفوائد برقم: 4124، 4125، وأخرجه إتحاف الخيرة المهرة بزوائد المسانيد العشرة برقم: 4931/1، وأخرجه السنن الصغير للبيهقي برقم: 1255»