The word “giả” doesn’t mean “person” as in the word “tác giả” (author) or “khán giả” (audience). It plays a different part in the phrase “Ác giả ác báo”.
It is put behind a paragraph, a clause to mark that if you reach to the word “giả” when reading or speaking, you have to pause for a sec then continue.
All of this is for emphasizing the thing, the situation.
Ác giả ác báo is defined as “if you are bad and not kind, bad things will happen to you” (what goes around comes around)
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