Sayyiduna Zayd bin Khalid al-Juhani (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever gives a fasting person something to break his fast with will have a reward like his, and his reward will not be reduced at all. And whoever equips a fighter in the path of Allah will have a reward like his, and his reward will not be reduced at all."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8138