How much frankincense accompanied the Lechem ha'Panim?
Rashi: Two bowls of frankincense accompaniy the Lechem ha'Panim, one small bowl-full for each row of loaves. 1
See Sifsei Chachamim. See also 24:7:1.1:1.
Seeing as the Torah writes Al ha'Ma'arachh" (singular) how do we know that the Kohen places one bowl on each row?
Sifra: We learn it from the previous Pasuk, where "ha'Ma'areches" incorporated two rows, as the Pasuk itself indicates.
Where exactly, did they place the two bowls of frankincense?
Menachos, 98a: They placed the two bowls (not on but) next to 1 the two rows of loaves (on the Shulchan).
Menachos, 98a: Like "Vesakosa al ha'Aron es ha'Paroches" - in Pikudei Sh'mos 40:2. See Torah Temimah, note 16.
What does the Torah mean when it writes "Vehaysah la'Lechem le'Azkarah"?
Rashi #1: It means that, since the Loaves are entirely eaten by the Kohanim, the frankincense is burned on the Mizbe'ach to represent them. 1
Rashi #2 (in Yeshayah): It means 'to be burned, since "Azkarah" is an expression of 'Haktarah' (burning).
Rashi #3 (in Zeachim, 63a): It means that it will serve as the memorial portion, to permit the loaves to be eaten, in the same way as the Kometz permite the remainder of the Minchah. 2
Sifra: It means that the Levonah 'binds' the Loaves, inasmuch as it prevents them from being eaten until it is burned and it renders them Pigul or Pasul in the eent that it becomes Pigul or Pasul.
Like the blood and the fat-pieces of a Korban represent the body of the animal, which is eaten, either by the Kohanim or by the owner.
Rashi: In fact, their removal from the Shulchan in the Heichal is the equivalent of the Kemitzah of the Menachos that require Kemitzah. Rashi (in Pesachim, 58a): The removal, which takes place on Shabbos ? as the next Pasuk indicates ? is immediately followed by the Lechem's distribution.