Isaiah 36:21

But they, the men of Judah, also those on the wall, held their peace and answered him not a word, for a single incautious remark might have worked great harm; for the king's commandment was, saying, Answer him not.

Then, after Hezekiah had laid his matter before the Lord in prayer, Isaiah, the son of Amoz, sent unto Hezekiah, saying, Thus saith the Lord God of Israel, Whereas thou hast prayed to Me against Sennacherib, king of Assyria: