And he read from it facing the square before the Water Gate from early morning until midday, in the presence of the men and the women and those who could understand. And the ears of all the people were attentive to the Book of the Law.
The Word of God can affect massive change when people submit to it. This section of the book of Nehemiah documents the spiritual renewal in Jerusalem among the exiles who returned and rebuilt the walls of the city. It began with leaders who were committed to the scriptures. From that commitment came a genuine spiritual renewal that was the clear work of God.
Nehemiah and his leadership team along with Ezra the scribe assembled the Israelites in the public square at the Water Gate in Jerusalem. They built a special speaking platform from which Ezra read the "Book of the Law" (probably the entirety of Deuteronomy) to the people. This took at least 3 hours (depending on the meaning of "early morning") and all the people stood to pay attention to what was read.
It appears that after the reading a large group of men (13 are mentioned by name as well as a group of Levites unnamed) then divided up the crowd among them to exegete the entire Book of the Law so that everyone assembled clearly understood it (Nehemiah 8:7-8). That had to take some time. I'm thinking this was an all-day preaching and application assembly. In the end, deep-felt commitment sprang from hearts affected by God's holy Word (Nehemiah 8:9-12) that started with weeping over sin and ended with a joyous feast and celebration.
God's Word changes us when we understand it. We are moved to fresh obedience, to heartfelt repentance, to unspeakable joy, and to obedient worship. All these will spring up in God's people, sometimes simultaneously, when we listen to and understand God's Word.