Numbers 4:13

The altar. That is, the bronze altar of burnt offerings (Ex. 27:1–3).

A purple cloth. The purple or deep red cloth may have been used as a distinctive mark, because this was the altar of burnt offerings that stood in the courtyard, and not in the holy place.

This verse speaks of bearing away the “ashes.” Many commentators say nothing about this for the reason that the meaning of the word thus translated is uncertain. The root verb is used but 11 times in the OT and is generally rendered “maketh …fat” (Prov. 15:30) or “shall be made fat” (Prov. 11:25; 13:4; 28:25; Isa. 34:7). The noun, found seven times, is without exception translated “fatness.” The same root, used eight times and listed as a separate noun, is translated “ashes.” The adjective, three times in the OT, is rendered “fat.” All of this suggests that the reference may be to the burned fat or grease that accumulated from the burnt offerings.