Need help finding Augustine references

[Scoop22]

In the following paragraph (from here: Philip Schaff: ANF03. Latin Christianity: Its Founder, Tertullian - Christian Classics Ethereal Library):

"In St. Augustine’s time, when moral theology became systematized in the West, by his mighty genius and influence, the following were recognized degrees of guilt: (1.) Sins deserving excommunication. (2.) Sins requiring to be confessed to the brother offended in order to God’s forgiveness, and (3.) sins covered by God’s gracious covenant, when daily confessed in the Lord’s Prayer, in public, or in private. And this classification was professedly based on Holy Scripture. Thus: (1.) on the text—“To deliver such an one unto Satan, etc.” (1 Cor. v. 4–5). (2.) On the text—(Matt. xviii. 15), “Confess your sins one to another, brethren” (James v. 16), and (3.) on the text—(Matt. vi. 12) “Forgive us our trespasses as we forgive them that trespass against us.” This last St. Augustine5190 regards as the “daily medication” of our ordinary life, habitual penitence and faith and the baptismal covenant being presupposed."

Does anyone know of any references on Augustines writings to support these "degrees of guilt"?

 

[Quid est Veritas?]

The sermon to the Catechumens spring to mind:

CHURCH FATHERS: Sermon to Catechumens on the Creed (St. Augustine)

15. Forgiveness of sins. You have [this article of] the Creed perfectly in you when you receive Baptism. Let none say, I have done this or that sin: perchance that is not forgiven me. What have you done? How great a sin have you done? Name any heinous thing you have committed, heavy, horrible, which you shudder even to think of: have done what you will: have you killed Christ? There is not than that deed any worse, because also than Christ there is nothing better. What a dreadful thing is it to kill Christ! Yet the Jews killed Him, and many afterwards believed on Him and drank His blood: they are forgiven the sin which they committed. When you have been baptized, hold fast a good life in the commandments of God, that you may guard your Baptism even unto the end. I do not tell you that you will live here without sin; but they are venial, without which this life is not. For the sake of all sins was Baptism provided; for the sake of light sins, without which we cannot be, was prayer provided. What has the Prayer? Forgive us our debts, as we also forgive our debtors. Once for all we have washing in Baptism, every day we have washing in prayer. Only, do not commit those things for which you must needs be separated from Christ's body: which be far from you! For those whom you have seen doing penance, have committed heinous things, either adulteries or some enormous crimes: for these they do penance. Because if theirs had been light sins, to blot out these daily prayer would suffice.

16. In three ways then are sins remitted in the Church; by Baptism, by prayer, by the greater humility of penance; yet God does not remit sins but to the baptized. The very sins which He remits first, He remits not but to the baptized. When? When they are baptized. The sins which are after remitted upon prayer, upon penance, to whom He remits, it is to the baptized that He remits. For how can they say, Our Father, who are not yet born sons? The Catechumens, so long as they be such, have upon them all their sins. If Catechumens, how much more Pagans? How much more heretics? But to heretics we do not change their baptism. Why? Because they have baptism in the same way as a deserter has the soldier's mark: just so these also have Baptism; they have it, but to be condemned thereby, not crowned. And yet if the deserter himself, being amended, begin to do duty as a soldier, does any man dare to change his mark?

 

[Scoop22]

Thank you