Jamieson, Fausset and Brown on Nehemiah 8:4

4. Ezra ... stood upon a pulpit of wood--Not made in the form known to us, but only a raised scaffold or platform, broad enough to allow fourteen persons to stand with ease upon it. Ezra's duty was very laborious, as he continued reading aloud from morning until midday, but his labor was lightened by the aid of the other priests present. Their presence was of importance, partly to show their cordial agreement with Ezra's declaration of divine truth; and partly to take their share with him in the important duty of publicly reading and expounding the Scripture.