'Thirty' in the Bible

Shiza the Reubenite's son Adina, a leader of the descendants of Reuben, along with thirty others with him,

Ishmaiah from Gibeon (who was one of the elite among the Thirty and in charge over them), Jeremiah, Jahaziel, Johanan, Jozabad from Gederah,

Then the Spirit came upon Amasai, leader of the Thirty, and he said, "David, we belong to you; we're with you, son of Jesse! Peace, peace to you, and peace to the one who helps you! For your deliverer is your God."

This was the same Benaiah who was one of the elite men of the Thirty and in command of the Thirty. His son Ammizabad was responsible for his division.