en_tn/1co/05/01.md

that is not even permitted among the Gentiles

"that not even the Gentiles permit." (See: rc://en/ta/man/translate/figs-activepassive)

father's wife

the wife of his father, but not likely his mother.

Should you not mourn instead?

This rhetorical question is used to scold the Corinthians. AT: "You should mourn over this instead!" (See: rc://en/ta/man/translate/figs-rquestion)

The one who did this must be removed from among you

"You must remove the one who did this from among you." (See: rc://en/ta/man/translate/figs-activepassive)