Sunan at-Tirmithiy كتاب الصوم باب ما جاء فى فضل من فطر صائما
The Messenger of God, peace and blessings of God be upon him, said, "Whoever feeds(1) a fasting person has the same reward as that person, yet this in no way lessens the reward of the fasting person." Footnotes: (1) i.e. when it is time to break the fast. Click on ḥadīth to read more