Charles Ellicott Commentary Nehemiah 8:6

"and Ezra blessed Jehovah, the great God. And all the people answered, Amen, Amen, with the lifting up of their hands: and they bowed their heads, and worshipped Jehovah with their faces to the ground." — Nehemiah 8:6 (ASV)

And Ezra blessed the Lord. — The book was formally and solemnly opened before the people. At this request the multitude arose, and, after a doxology offered by Ezra, they all uttered a double Amen, with lifting up of their hands, as a sign of their most fervent assent; and then with faces bowed to the ground, as a sign of adoration.

The great God is Nehemiah’s expression, not Ezra’s; the sentence used is not reported.