How big was king Og's bed?

Nine cubits long and four cubits wide

For only Og king of Bashan remained of the remnant of giants; behold his bedstead was a bedstead of iron; is it not in Rabbath of the children of Ammon? nine cubits was the length thereof, and four cubits the breadth of it, after the cubit of a man. Deuteronomy 3:11