Related for Megillah 17:6

אלא לא קשיא כאן במגילה כאן בספרים מגילה מ"ט דכתיב בה ככתבם וכלשונם מאי תרגום שכתבו מקרא איכא

Rather there is no contradiction; the one statement [in the baraita] refers to the Megillah, the other to the other books [of the Scripture]. What is the reason in the case of the Megillah? — Because it is written in regard to it, “According to their writing and according to their language” (Esther 1:20). What case of Aramaic being written in Hebrew is possible here?

Jerusalem Talmud Megillah