Leviticus 6:3

And the priest shall dress himself in vestments of linen, and put drawers of linen upon his flesh; and shall separate the ashes which the fire (maketh) in consuming the burnt offering upon the altar, and shall place them at the side of the altar.

a smock [Hebrew: middo] The Sages said [Yoma 23b] that this smock was tailored to his measurements [Hebrew: middato].

on his flesh a euphemism for his genitals (as in, “a flowing from his flesh” [15:2])

which the fire consumes i.e., which is left over from what the fire has consumed

beside the Altar by its eastern side

AND THE PRIEST SHALL PUT ON ‘MIDO’ (HIS GARMENT OF) LINEN. “This is a reference to the k’toneth (tunic). Why then does Scripture here call it mido [which means ‘his measure’]? It is to indicate that the tunic is to be made to his measure. AND HIS LINEN BREECHES SHALL HE PUT UPON HIS FLESH — that there should be nothing interposing between them.” This is Rashi’s language.
Now the [daily] removal of the ashes [from the altar, which is the subject-matter of this verse], must be done with the priest wearing the [four] garments of priesthood, as no Service can be performed with only two of the [four] garments! However, He mentioned only these two garments because of new points that are added here to them, namely, that the tunic must be made to the priest’s measure. This means to say that if it was raised [above his feet], being so short that it did not reach his feet, and he performed therein one of the acts of offering, his Service is invalid. It further teaches that there must be nothing intervening between the breeches and his flesh. But the law requires equally that the priest who removes the ashes from the altar should wear all [four] priestly garments, for since Scripture mentioned that the removing of the ashes must be done with priestly garments, we know [automatically] that it requires four for the common priest and eight for the High Priest. So also is it explained in the second chapter of Tractate Yoma and in Torath Kohanim: 2:1. “Why does Scripture repeat the term yilbash [‘he shall put on’ — ‘V’lavash hakohein’ (and the priest shall put on) his linen garment, and his linen breeches ‘yilbash’ (he shall put) upon his flesh]? It is to include the turban and the belt” [which the priest is also to put on for the removing of the ashes].
Now Onkelos translated the word mido as levushin [“garments” — as opposed to Rashi’s interpretation, according to which it refers only to one garment, the tunic]. It would appear then that according to Onkelos, the word mido is a term which includes all of the priest’s garments, as if the verse were stating, “and the priest shall put on linen garments.” Similarly we are to understand the expressions: ‘madav’ (his clothes) rent; that cometh down upon the collar ‘midothav’, which means upon the edge of his garments; girded with ‘mido’ (his apparel) of war, which means his garments. This then will be in accordance with the opinion of the Sage who says (Exodus 39:28, Vol. II, p. 614). that the belt of the common priest was unlike the belt of the High Priest. as an inclusive term for “all” the priest’s garments, and the verse states, and the priest shall put on ‘mido’ (his ‘garments’ of) linen, Onkelos accordingly must agree with Rabbi Dosa that the belt of the common priest was unlike that of the High Priest, as the belt of the common priest was only of linen. Hence it states that the common priest shall put on all his garments of linen which includes the belt.

מדו, as in Numbers 23,18 בנו צפור, [in both instances the letter ו at the end is something extraneous. Ed.] It again occurs in that mode in Numbers 24,3. Basically the word מד refers to some kind of garment, especially work oriented or vocation oriented, as in Samuel I 4,12 where the expression ומדיו קרועים, refer to a “torn uniform.”

והרים את הדשן, the procedure known as תרומת הדשן, the cleaning out of the ash, a procedure which could be performed all day long. It was mandatory to do this before the offering of the daily morning burnt offering. However, the removal from the camp of the ash could be taken care of any time during the day and not daily. When the top of the altar was too full it would be removed. (verse 4)