This refers to Paul's previous letter to these Corinthian believers where he rebuked them for their acceptance of a believer's sexual immorality with his father's wife.
"you suffered no loss because we rebuked you." This means that although the letter caused them sorrow, they eventually benefited from the letter because it led them to repentance. AT: "so that we did not harm you in any way" (See: [[rc://en/ta/man/translate/figs-idiom]])
The word "repentance" may be repeated to clarify its relationship to what precedes it and what follows it. AT: "For godly sorrow produces repentance, and repentance leads to salvation" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
# without regret
Possible meanings are 1) Paul has no regret that he caused them sorrow because that sorrow led to their repentance and salvation or 2) the Corinthians will not regret experiencing sorrow because it led to their repentance and salvation.
This kind of sorrow leads to death instead of salvation because it does not produce repentance. AT: "Worldly sorrow, however, leads to spiritual death" (See: [[rc://en/ta/man/translate/figs-explicit]])