It was foursquare; they made the breastplate double: a span was the length thereof, and a span the breadth thereof, being double.
It was foursquare; they made the breastplate double: a span was the length thereof, and a span the breadth thereof, being doubled.
The breastplate was a [hand's] span square when doubled over.
They made the chest pendant square and doubled, nine inches long and nine inches wide when doubled.
with four equal sides, doubled, of the measure of the palm of a hand.
Four-square, double, of the measure of a span.