Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "The most excellent of those who take part in battle in the path of Allah is the one who serves them, then the one who brings them news (of the enemy). And the one with the most special rank in the presence of Allah Almighty is the one who fasts. And whoever brings a waterskin for his companions in the path of Allah will precede them to Paradise by seventy degrees (the narrator is unsure; perhaps the words are:) seventy years."
Al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains a narrator, Anbasah bin Mihran, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجهاد / 9508