A silent fool is counted wise

मूर्खोऽपि शोभते तावत्
सभायां वस्त्रवेष्टितः ।
तावच्च शोभते मूर्खः
यावत्किञ्चिन्न भाषते ॥

- हितोपदेशः

Even a fool shines in an assembly (of the wise) if he is well dressed. So long does a fool shine as long as he says nothing.

Silence is a virtue of fools.
A silent fool is counted wise.
Better to be silent and thought a fool than to speak and remove all doubt.