Ex 25:4

25:4 blue. Or, violet. Violet and purple dyes were obtained from shellfish; scarlet from an insect of the cochineal type. These colors were precious because of the cost of the dye. The blue of the tabernacle came to be particularly associated with the Lord (Num. 15:38).

fine twined linen. The fine linen was probably Egyptian.

goats’ hair. The goat hair was undyed. It was to be used as a first covering for the tabernacle, and over it other skins would be placed (26:14).