Numbers 4:11

And they shall put a blue cloth for a cover on the golden altar, and shall cover it with a blue skin cover, and put in its staves.

And upon the golden altar they shall spread a cloth of blue, and cover it with a covering of badgers’ skins, and shall put to the staves thereof:

“On the golden altar they shall spread a blue cloth, and cover it with a covering of sealskin, and shall put in its poles.