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.

17-20. Cut ye not off the tribe of the families of the Kohathites from among the Levites, &c.—a solemn admonition to Moses and Aaron to beware, lest, by any negligence on their part, disorder and improprieties should creep in, and to take the greatest care that all the parts of this important service be apportioned to the proper parties, lest the Kohathites should be disqualified for their high and honorable duties. The guilt of their death would be incurred by the superintending priest, if he failed to give proper directions or allowed any irreverent familiarity with sacred things.