It is narrated from Sayyiduna Salman al-Farisi (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever gives a fasting person food to break his fast in Ramadan from lawful earnings, the angels pray for mercy upon him."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6136