4 Finally, beloved brethren, the divine admonition in the Scriptures, as well old as new, has never failed, has never been silent in urging God's people always and everywhere to works of mercy; and in the strain and exhortation of the Holy Spirit, every one who is instructed into the hope of the heavenly kingdom is commanded to give alms. God commands and prescribes to Isaiah: “Cry,” says He, “with strength, and spare not. Lift up your voice as a trumpet, and declare to my people their transgressions, and to the house of Jacob their sins.” And when He had commanded their sins to be charged upon them, and with the full force of His indignation had set forth their iniquities, and had said, that not even though they should use supplications, and prayers, and fastings, should they be able to make atonement for their sins; nor, if they were clothed in sackcloth and ashes, be able to soften God's anger, yet in the last part showing that God can be appeased by almsgiving alone, he added, saying, “Break your bread to the hungry, and bring the poor that are without a home into your house.
If you see the naked, clothe him; and despise not the household of your own seed. Then shall your light break forth in season, and your garments shall arise speedily; and righteousness shall go before you, and the glory of God shall surround you. Then shall you cry, and God shall hear you; while yet you are speaking, He shall say, Here I am.”
Source: The Treatises of Cyprian (New Advent)