Exodus 39:3

And they did beat the gold into thin plates, and cut it into wires, to work it in the blue, and in the purple, and in the scarlet, and in the fine linen, with cunning work.

Cross-references

Exodus 28:5 commands gathering gold and colored yarns; this verse shows them being hammered and worked into the ephod.

Exodus 26:1 uses the same materials and skilled work for tabernacle curtains, paralleling the ephod's gold thread technique.