Of Righteousness
Moreover, concerning the righteousness which the law enjoined, confirmatory utterances are found both with the prophets and in the Gospels, because they all spoke inspired by one Spirit of God. Isaiah accordingly spoke thus: “Put away the evil of your doings from your souls; learn to do well, seek judgment, relieve the oppressed, judge the fatherless, plead for the widow.” And again the same prophet said: “Loose every band of wickedness, dissolve every oppressive contract, let the oppressed go free, and tear up every unrighteous bond.
Deal out your bread to the hungry, and bring the houseless poor to your home. When you see the naked, cover him, and hide not yourself from your own flesh. Then shall your light break forth as the morning, and your health shall spring forth speedily, and your righteousness shall go before you.” In like manner also Jeremiah says: “Stand in the ways, and see, and ask which is the good way of the Lord your God, and walk in it and you shall find rest for your souls. Judge just judgment, for in this is the will of the Lord your God.” So also says Hosea: “Keep judgment, and draw near to your God, who established the heavens and created the earth.” And another, Joel, spoke in agreement with these: “Gather the people, sanctify the congregation, assemble the elders, gather the children that are in arms; let the bridegroom go forth of his chamber, and the bride out of her closet, and pray to the Lord your God urgently that he may have mercy upon you, and blot out your sins.” In like manner also another, Zachariah: “Thus says the Lord Almighty, Execute true judgment, and show mercy and compassion every man to his brother; and oppress not the widow, nor the fatherless, nor the stranger; and let none of you imagine evil against his brother in your heart, says the Lord Almighty.”
Source: Theophilus to Autolycus (New Advent)