'Thirty' in the Bible

And three of the thirty chiefs went down to the rock to David, to the cave of Adullam, when the army of the Philistines was encamped in the valley of Rephaim.

Behold, he was honoured above the thirty, but he did not attain to the first three. And David set him in his council.

Adina the son of Shiza the Reubenite, a captain of the Reubenites, and thirty with him;

and Jishmaiah the Gibeonite, a mighty man among the thirty, and over the thirty; and Jeremiah, and Jahaziel, and Johanan, and Jozabad the Gederathite.

of the sons of Gershom, Joel the chief, and his brethren a hundred and thirty;

And the Levites were numbered from thirty years old and upward; and their number, by their polls, man by man, was thirty-eight thousand.

This Benaiah was a mighty man among the thirty, and above the thirty; and in his division was Ammizabad his son.