Midrash sa Mga Bilang 4:13: Bamidbar Rabbah & Sifra

“They shall remove the ashes from the altar and spread a cloth of purple wool over it. They shall place upon it all its utensils with which they serve upon it the fire-pans, the forks, the shovels, and the basins, all the utensils of the altar; and they shall spread upon it a covering of the hide of a taḥash, and place its staves” (Numbers 4:13–14).
The bronze altar that stood in the Courtyard, they would remove the ashes from upon it and would spread a cloth of purple wool to separate between it and the utensils that are placed upon it. That is what is written: “They shall remove the ashes from the altar and spread a cloth of purple wool over it.” The altar of the burnt offering, because it was not inside, they would not cover it with sky-blue wool, but rather with purple wool, because it would weave Israel from sin,²⁴Buttress Israel against sin. as upon it they would sacrifice daily offerings each day and sin offerings, guilt offerings, burnt offerings, and peace offerings. After they would cover it they would place its utensils on it, as it is written: “They shall place upon it all its utensils with which they serve [upon it].”
It was taught: “A perpetual fire” (Leviticus 6:6) – even on Shabbat, even in impurity; “it shall not be extinguished” (Leviticus 6:6) – even during journeys. What would they do to it? They would overturn a pot over it, this is the statement of Rabbi Yehuda. Rabbi Shimon says: Even during the journeys they would remove the ashes from the altar, as it is stated: “They shall remove the ashes from the altar.”²⁵Sifra, Tzav 2:10. According to the opinion of Rabbi Yehuda, it works out well that this pot was not mentioned with the altar utensils on the journey, as it is stated: “The fire pans, the forks, the shovels, and the basins,” but it does not mention pots. Why? It is because they would overturn them over the fire. According to the opinion of Rabbi Shimon, “all the utensils of the altar,” is to include the pots. According to the opinion of Rabbi Shimon, “they shall remove the ashes from the altar” works out well. According to the opinion of Rabbi Yehuda, they would remove the ashes from it, they would place fire there, and then overturn the pot over it so that it would not be extinguished.
Although there was a distinction between the vessels that were situated inside and the vessels standing outside regarding the cloth of sky-blue wool; however, regarding the taḥash, these and those are equal, as it is stated: “They shall spread upon it a covering of the hide of a taḥash, and place its staves.”

6) "of all the mitzvoth of the L–rd": I would understand this as meaning both positive and negative commandments; it is, therefore, written: "which may not be done." (only negative commandments are being referred to.) ("which may not be done" is written four times [Bamidbar 4:2, Bamidbar 4:13, Bamidbar 4:22, Bamidbar 4:28] for four exclusions): I would exclude (from a sin-offering) a lesser positive commandment, but not a greater one (e.g., the eradication of idolatry); it is, therefore, written: "which may not be done." (Only negative commandments are intended.) I would exclude (transgression of) mitzvoth not punishable by kareth, but not pesach and circumcision (transgression of which is) punishable by kareth; it is, therefore, written: "which may not be done." I would exclude pesach, which is not (a) constant (observance), but not circumcision, which is constant; it is, therefore, written: "which may not be done." But then I would exclude the positive commandment of (separation from a niddah (before the time of her flow); it is, therefore, written: "of all the mitzvoth of the L–rd," to include (for a sin-offering one who did not separate and was "surprised" by her flow). Why do you see fit to exclude all (positive) commandments and to include that of niddah? Since Scripture included and excluded, why do I exclude all the (positive) commandments? Because they have no counterpart in a negative commandment. And I include the positive commandment of niddah because it has its counterpart in a negative commandment (viz. [Bamidbar 18:19]: "And to a woman in the niddah state of her uncleanliness you shall not come near.")

10) Whence is it derived that nothing is to take precedence to the morning tamid? From "upon it the burnt-offering," (implying that nothing is to take precedence to it). Whence is it to be derived that nothing is offered up later than the afternoon tamid? From "upon it (the afternoon tamid, the shelamim, lit., the "completers," i.e., complete all of the offerings with it). (Vayikra 6:6) ("A continuous fire shall burn upon the altar; it shall not be extinguished.") "continuous" — (The wood pile is to be made for the temidim and the mussafim) even on the Sabbath; "continuous" — even (if the Cohanim are) in a state of tumah. "it shall not be extinguished" — even during their journeyings. What did they do (to keep the fire from going out)? They inverted a psachter (a large vessel) over it. These are the words of R. Yehudah. R. Shimon says: In their journeyings they would remove the fire from the altar (and place it in a vessel until they camped), as it is written (Bamidbar 4:13): "And they shall remove the fire from the altar and spread upon it (the vessel) a purple cloth."