He was one of those who stood beside Ezra (the scholar) when he explained the Book of the Law.
Nehemiah 8:4And Ezra the scribe stood on a wooden platform that had been made for the purpose. And beside him stood Mattithiah, Shema, Ananiah, Uriah, Hilkiah, and Maaseiah on his right hand; and on his left hand Pedaiah, Mishael, Malchijah, Hashum, Hashbaddanah, Zechariah, and Meshullam.
He was a leader or Levite who led the people during the return of Nehemiah (the governor). He resolved to obey God and participated in the sealing.