What were the "Bigdei ha'Serad"?
Rashi and Seforno: They were the covers of Techeiles, Argaman and Tola'as Shani 1 with which Aharon and his sons covered the Keilim before they traveled. 2
Ramban (citing Yoma 72a-b) and Da'as Zekenim: The Bigdei S'rad are synonymous with Bigdei Kehunah.
Refer to 31:10:2:2*..
As described at the end of Parshas Bamidbar (Rashi and Rashbam). It cannot be referring to the Bigdei Kehunah a. because the Torah continues "ve'es Bigdei ha'Kodesh le'Aharon ha'Kohen ... "; and b. because the Pasuk 39:1, states that the Bigdei ha'Serad were made of Techeiles, Argaman and Tola'as Shani, and does not mention Sheish (linen) - whereas all the Bigdei Kehunah which contained Argaman and Tola'as Shani also contained Sheish. The Torah does not provide specifications, because they had no specific shape or size, and they commonly made network coverings, to fit over the Keilim (Seforno).
Why were they called "Bigdei ha'Serad"??
Rashi , Rashbam and R. Bachye #1: It means ?covers (that are knitted? [plaited with holes ? Rashi and Rashbam] ) 1 2 - to cover the Keilim of the Mishkan when they traveled. 3
Ramban #2: It is synonymous with the Bigdei Kehunah of Aharon, and were so-called because they were worn by someone who was unique 6 (the Kohen Gadol). 7
R. Bachye #2 (citing Yoma 72b): They are called ?Bigdei Seraad?, because, if not for the Bigdei ha?Serad, not a remnant (?Sarid?) or a refugee would remain from Yisrael. 8
R. Bachye #3 (according o Kabalah): The ?Hey? in ?ha?Serad? represents the second ?Hey? in the Name Havayah ? which the Torah hints by the Bigdei ha?Serad because the Keilim are hidden and revealed by them, just as the Great Name of Hashem is hidden by the ?Hey?and revealed by it.
See Targum Onkelos in Terumah, 27:9 on the word "Kela'im" and on the word "Michbar" (Ibid. 27:4). Refer also to 27:9:1:1* The Ramban objects to this explanation however, since it is not appropriate to cover the holy Keilim with knitted cloths with holes, and for a number of other reasons ? Refer to 31:10:3:1*.
R. Bachye: They are knitted like curtains ? ?Kela?im?, which Onkelos in Terumah 27:11 translates as ?Seradin?. See also R. Bachye citing Yoma 72b and the Yerushalmi and R. Chavel?s footnotes.
See Bamidbar chapter 4.
Ramban: As in Yo'el, 3:5 and in Yehoshua, 10:20.
See Ramban, DH 've?ha'Oleh mi'Divrei Raboseinu'.
See R. Bachye, ibid., regarding the story of Shimon ha?Tzadik, who saved Yisrael from Alexander the Great, when he went to meet him wearing the Bigdei Kehunah.
Why did the Torah not instruct Moshe to make the Bigdei ha'Serad like it did all the other parts of the Mishkan?
Ramban (explaining Rashi) 1 : Hashem, not particular as to how they covered the Keilim, left it up to them to make whatever covers they saw fit. Based on their decision to make individual covers of Techeiles, Argaman and Tola'as Shani, Hashem instructed them to use the Techeiles cover for the Aron, the Argamon for the Mizbe'ach and the Tola'as Shani for the Shulchan.
R. Bachye: The Torah repeated ?Ve?asu Bigdei Kodesh 2 le?Aharon Achicha u?le?Vanav? ? in Tetzaveh 28:4 - with reference to other Bigdei Kodesh - the Bigdei ha?Serad, 3
Refer to 31:10:1:1. The Ramban himself poses the question as one of the proof that the Bigdei ha?SErad are synonymous with the BIgdei Kehunah.
And not ?es Bigdei ha?Kodesh?. See R. Bachye.
R. Bachye: Which also fall under the heading ?Bigdei ha?Kodesh? because they serve the holy Keilim and cover them.
