'Doubled' in the Bible

Square shall it be, doubled; a span the length thereof, and a span the breadth thereof.

It was square; double did they make the breastplate, a span the length thereof, and a span the breadth thereof, doubled.

And thou, son of man, prophesy, and smite thy hands together; for the strokes of the sword shall be doubled the third time: it is the sword of the slain, the sword that hath slain the great one, which encompasseth them privily.