Hezekiah received the letter - The inscriptions show that scribes accompanied the Assyrian armies, with the materials of their craft, so that such a dispatch might be easily drawn up. As Hezekiah himself “read” it, we may presume that it was in the Hebrew tongue.
Related Commentaries of 2 Kings 19:14
2 Kings 19:14
14 And Hezekiah received the letter of the hand of the messengers, and read it: and Hezekiah went up into the house of the LORD, and spread it before the LORD.