Quotes from three early church fathers/writers concerning works of charity:

And if there is among them any that is poor and needy, and if they have no spare food, they fast two or three days in order to supply to the needy their lack of food. —The Apologist Aristides, 125 AD

We know many among us have who have given [sold] themselves into bondage, in order that they might ransom others. Many, too, have surrendered themselves to slavery, that with the price which they received for themselves, they might provide food for others.  —Clement of Rome, 96 AD

On that day in which you fast, you shall taste nothing except bread and water.  Of the foods which you were going to eat, reckon how much the food of that day when you fast was going to cost, and give the amount to a widow or orphan or one in need.  —Hermas of Rome, (c. 90-140)