9 It was square—a spana long and a span wide—and folded double.

Read Exodus 39:9 Using Other Translations

It was foursquare; they made the breastplate double: a span was the length thereof, and a span the breadth thereof, being doubled.
It was square. They made the breastpiece doubled, a span its length and a span its breadth when doubled.
He made the chestpiece of a single piece of cloth folded to form a pouch nine inches square.