6 Then they are to cover this with a dolphin skin, spread a solid blue cloth on top, and insert the poles.

Matthew Henry's Commentary on Numbers 4:6

Commentary on Numbers 4:4-20

(Read Numbers 4:4-20)

The Kohathites were to carry the holy things of the tabernacle. All the holy things were to be covered; not only for security and respect, but to keep them from being seen. This not only marked the reverence due to holy things, but the mystery of the things signified by those types, and the darkness of the dispensation. But now, through Christ, the case is altered, and we are encouraged to come boldly to the throne of grace.