'Four square' in the Bible

Four-square shall it be, doubled; a span its length, and a span its breadth.

A cubit its length, a cubit its breadth; it shall be four-square; and two cubits its height: its horns out of it.

And he will make the altar of burnt-offering of acacia wood: five cubits its length, and five cubits its breadth; four-square; and three cubits its height

It was four-square; they made the breast-plate double: a span its length, and a span its breadth; double.