Numbers 4:13

And they shall take away the ashes from the altar, and spread a purple cloth thereon:

Exodus 27:1-8

And thou shalt make the altar of acacia wood, five cubits long, and five cubits broad; the altar shall be foursquare: and the height thereof shall be three cubits.

Exodus 39:1

And of the blue, and purple, and scarlet, they made finely wrought garments, for ministering in the holy place, and made the holy garments for Aaron; as Jehovah commanded Moses.

Exodus 39:41

the finely wrought garments for ministering in the holy place, and the holy garments for Aaron the priest, and the garments of his sons, to minister in the priest's office.

Leviticus 6:12-13

And the fire upon the altar shall be kept burning thereon, it shall not go out; and the priest shall burn wood on it every morning: and he shall lay the burnt-offering in order upon it, and shall burn thereon the fat of the peace-offerings.

Numbers 4:6-9

and shall put thereon a covering of sealskin, and shall spread over it a cloth all of blue, and shall put in the staves thereof.

Numbers 4:11-12

And upon the golden altar they shall spread a cloth of blue, and cover it with a covering of sealskin, and shall put in the staves thereof:

Treasury of Scripture Knowledge

Summary

And they shall take away the ashes from the altar, and spread a purple cloth thereon:

The embers of the sacred fire seem to have been removed in the grate, which was carried apart from the brazen altar; both being covered from view by purple cloths

General references

Bible References

The embers of the sacred fire seem to have been removed in the grate, which was carried apart from the brazen altar; both being covered from view by purple cloths

Numbers 4:6
and shall put thereon a covering of sealskin, and shall spread over it a cloth all of blue, and shall put in the staves thereof.
Exodus 27:3
And thou shalt make its pots to take away its ashes, and its shovels, and its basins, and its flesh-hooks, and its firepans: all the vessels thereof thou shalt make of brass.
Exodus 39:1
And of the blue, and purple, and scarlet, they made finely wrought garments, for ministering in the holy place, and made the holy garments for Aaron; as Jehovah commanded Moses.
Leviticus 6:12
And the fire upon the altar shall be kept burning thereon, it shall not go out; and the priest shall burn wood on it every morning: and he shall lay the burnt-offering in order upon it, and shall burn thereon the fat of the peace-offerings.

General references

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.

American Standard Version Public Domain