It was narrated that Zayd ibn Khaalid al-Juhani said: The Messenger of Allaah (sallallaahu ’alayhi wa sallam) said: "Whoever gives iftaar to one who is fasting will have a reward like his, without that detracting from the reward of the fasting person in the slightest."
Narrated by al-Tirmidhi, 807; Ibn Maajah, 1746.