Megilah2: 1
הַקּוֹרֵא אֶת הַמְּגִלָּה לְמַפְרֵעַ — לֹא יָצָא. קְרָאָהּ עַל פֶּה, קְרָאָהּ תַּרְגּוּם, בְּכָל לָשׁוֹן — לֹא יָצָא. אֲבָל קוֹרִין אוֹתָהּ לַלּוֹעֲזוֹת בְּלַעַז. וְהַלּוֹעֵז שֶׁשָּׁמַע אַשּׁוּרִית — יָצָא.
[If] someone read the Megillah out of sequence, he has not fulfilled his obligation. [If] he read it by heart, [or if] he read it in Targum [or] in any other language, he has not fulfilled his obligation. However, we may read it for those who speak a foreign language in a foreign language. One who speaks a foreign language and heard it [read in Hebrew that was written] in Assyrian [script] has fulfilled his obligation.