Chapter 41, “The Case of Public Repentance” (pp. 244-246)
When someone has fallen into an obvious sin the repentance and forgiveness are to be public as well. Walther defines the situation on p. 244. “A manifest fall into sin is at the same time a sin against the whole congregation. So a public reconciliation is necessary.” The purpose is not for shame but to restore trust. Walther is clear on p. 245 that the public confession and repentance is intended for open and public sin that causes offense. Private sins are handled privately.
Walther does observe that in general forgiveness should not be delayed. If a person falls into sin and is immediately repentant the forgiveness should be immediate as well.