'Thirty' in the Bible

In the thirty-first year of Judah’s King Asa, Omri became king over Israel and reigned 12 years. He reigned six years in Tirzah,

Ahab son of Omri became king over Israel in the thirty-eighth year of Judah’s King Asa; Ahab son of Omri reigned over Israel in Samaria 22 years.

Now Ben-hadad king of Aram assembled his entire army. Thirty-two kings, along with horses and chariots, were with him. He marched up, besieged Samaria, and fought against it.