Exodus 39:9 in the World English Bible
It was square. They made the breastplate double. Its length was a span, and its width a span, being double.
Context
8 And he made the breastplate of cunning work, like the work of the ephod; of gold, blue, and purple, and scarlet, and fine twined linen.
9 It was foursquare; they made the breastplate double: a span was the length thereof, and a span the breadth thereof, being doubled.
10 And they set in it four rows of stones: the first row was a sardius, a topaz, and a carbuncle: this was the first row.