John Gill Commentary Numbers 4:8

"and they shall spread upon them a cloth of scarlet, and cover the same with a covering of sealskin, and shall put in the staves thereof." — Numbers 4:8 (ASV)

And they shall spread upon them a cloth of scarlet
Upon the dishes and other vessels belonging to the shewbread table, and on the shewbread itself:

and cover the same with a covering of badgers' skins ;
this was clearly the outward covering, and seems to confirm the observation made in (Numbers 4:6) ; that the same sort of covering was the outermost covering of the ark:

and shall put in the staves thereof ;
which belonged to the table, and were made to carry it with on occasion, from place to place; see (Exodus 25:27Exodus 25:28) ; and the same phrase being used as here of the staves of the ark in (Numbers 4:6) ; seems to confirm the sense of them there, that they were taken out and put in upon this occasion, though otherwise fixed.