C. F. Keil and Franz Delitzsch on Numbers 4:13-14

Num 4:13-14

The altar of burnt-offering was first of all to be cleansed from the ashes; a crimson cloth was then to be covered over it, and the whole of the furniture belonging to it to be placed upon the top; and lastly, the whole was to be covered with a sea-cow skin. The only thing not mentioned is the copper laver (Exo 30:18), probably because it was carried without any cover at all. The statement in the Septuagint and the Samaritan text, which follows Num 4:14. respecting its covering and conveyance upon a frame, is no doubt a spurious interpolation.