'Thirty' in the Bible

a son of thirty and two years was he in his reigning, and eight years he hath reigned in Jerusalem.

In the thirty and seventh year of Joash king of Judah reigned hath Jehoash son of Jehoahaz over Israel, in Samaria -- sixteen years,

In the thirty and eighth year of Azariah king of Judah reigned hath Zechariah son of Jeroboam over Israel, in Samaria, six months,

Shallum son of Jabesh hath reigned in the thirty and ninth year of Uzziah king of Judah, and he reigneth a month of days in Samaria;

In the thirty and ninth year of Azariah king of Judah reigned hath Menahem son of Gadi over Israel -- ten years in Samaria.

and Hezekiah king of Judah sendeth unto the king of Asshur to Lachish, saying, 'I have sinned, turn back from off me; that which thou puttest on me I bear;' and the king of Asshur layeth on Hezekiah king of Judah three hundred talents of silver, and thirty talents of gold,

A son of eight years is Josiah in his reigning, and thirty and one years he hath reigned in Jerusalem, and the name of his mother is Jedidah daughter of Adaiah of Boskath,

And it cometh to pass, in the thirty and seventh year of the removal of Jehoiachin king of Judah, in the twelfth month, in the twenty and seventh of the month hath Evil-Merodach king of Babylon lifted up, in the year of his reigning, the head of Jehoiachin king of Judah, out of the house of restraint,