Majma al-Zawaid — Hadith 4725

Asim bin Kulayb narrates: I heard Sayyiduna Iyad bin Marthad, or perhaps Marthad bin Iyad, narrating this hadith to a man: He asked the Prophet (peace and blessings be upon him) about a deed that would admit him into Paradise. The Prophet (peace and blessings be upon him) asked: "Is either of your parents alive?" He said: "No." The Prophet (peace and blessings be upon him) asked him three times, then said: "Give water to drink: when people are absent, carry the water to them, and when they are present (at the water), suffice them (that is, draw the water out for them)."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are the narrators of the Sahih.