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 food to break his fast, feeding him and giving him drink, will have a reward equal to his, without anything being reduced from his reward."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5250