What is the difference between "Avodas Avodah" and "Avodas Masa"?
Rashi #1: "Avodas Avodah" refers to the playing of the instruments - with cymbals and harps; one Avodah to enhance another Avodah, and "Avodas Masa" to the Avodah of carrying. 1
Rashi #2 (in Divrei Hayamim 2, 29:25): "Avodas Avodah" refers to the playing of the instruments 2 - with cymbals and harps; one Avodah to enhance another Avodah, 3 and "Avodas Masa" to the actual singing. 4
R. Bachye and Arachin, 11a: "Avodas Avodah" refers to the Avodah of Shir, which accompanoies the Avodas ha'Korbanos. 5 6
Da'as Zekenim, Hadar Zekenim and Rosh: "Avodas Avodah" refers to Shechitah, flaying and dissecting, Avodos of Kohanim [which a Zar is permitted to perform]. 7
Targum Yonasan: "Avodas Avodah" refers to guarding, 8 "Avodas Masa", to carrying.
See Sifsei Chachamim.
See R. Bachye who elaborates on the number of strings on the harp.
Hadar Zekenim: The Shirah that accompanies the Avodah of the Nesachim. See Sifsei Chachamim.
Rashi (Ibid.) and R. Bachye: As the Pasuk in Divrei Hayamim 1, 15:22 implies.
R. Bachye: As the Pasuk writes in Tehilim 100:2 "Ivdu es Hashem be'Simchah".
Arachin, Ibid.: In fact, it is the source of Shirah min ha'Torah - since it is the only Avodah that require another Avodah for it to be effective.
Presumably, "Avodas Masa" refers to carrying.
Which also accompanied the Avodas ha'Korbanos. See Na'ar Yonasan
What is the significance of the comparison of Avodas Avodah to Avodas Masa?
Chulin, 24a: It teaches uss that the age limit that pertains to Levi'im regarding the Avodas ha'Levi'im is confined to the era of the desert, when they carried the Keilim, but did not apply in Shiloh or in the Beis-Hamikdash. 1
See Torah Temimah, Be'ha'aloscha, 5:24. DH 'Vehinei Lo Nisba'er'. '.
QUESTIONS ON RASHI
Rashi writes that Avodas Avodah refer to Shir with cymbals, implying that they may do so only until the age of fifty. But later, in Beha'aloscha, 8:25, he explains that after fifty they continued with the Avodah of Shir?
Moshav Zekeinim (citing the Ri): We can distinguish between instrumental Shir - which is only until fifty - and verbal Shir - which is even later. 1
