Isaiah 36:21

But they held their peace -Hezekiah had commanded them not to answer. They were simply to hear what Rabshakeh had to propose, and to report to him, that he might decide on what course to pursue. It was a case also in which it was every way proper that they should be silent. There was so much insolence, self-confidence, blasphemy, the proposals were so degrading, and the claims were so arrogant, that it was not proper that they should enter into conference, or listen a moment to the terms proposed. Their minds also were so horror-stricken with the language of insolence and blasphemy, and their hearts so pained by the circumstances of the city, that they would not feel like replying to him.