Exodus 39:3

They did beat the gold into thin plates and cut it into wires. — This very primitive method of forming gold thread is nowhere else mentioned. It implies a ruder state of the art of metallurgy than we should have expected.

To work it in the blue. — The blue, the purple, the scarlet, and the white linen thread were woven into a patterned fabric. The gold was inserted afterwards in the way of embroidery. A similar practice prevailed in Egypt (Wilkinson, Ancient Egyptians, vol. iii., p. 128).