Isaiah 36:13
Then Rabshakeh stood, and cried with a loud voice in the Jews’ language, and said, Hear ye the words of the great king, the king of Assyria. Then Rabshakeh stood, and cried with a loud voice in the Jews’ language, and said, Hear ye the words of the great king, the king of Assyria.
He had been requested to speak in Syrian, yet in defiance of that request he lifted his voice to address the people themselves. Taking his stand, he cried out with a loud voice in the Jews' language so that those on Jerusalem's wall could hear the message sent by the Assyrian king. In doing so he exalted Assyria's ruler as the great king.
The public address was calculated to press Judah into surrender and submission to Assyria. At the same time it reviled God and worked to produce distrust of the Lord. It likewise urged Judah's leaders and people to distrust Hezekiah.