Why was the crowd silent when Hester endured her punishment?

One could
argue that the crowd are silent because, as Puritans, law and God's word are synonymous. Their
silence, therefore, can be interpreted as awestruck reverence for what they regard as the just
punishment offor the crime of adultery.

It's notable that, before Hester's
punishment and before she's released from prison, the Puritan women gathered outside have a lot
to say about Hester and her brazen defiance of law and convention. But then, at that point, she
hasn't been punished yet. It's only when Hester actually takes to the scaffold and is forced to
wear the scarlet letter that the women, along with the rest of the crowd, fall silent. Their
silence is a recognition that divine punishment is being meted out before their very eyes. God
is speaking, and they must listen in hushed reverence.