What is the meaning of "mi'Lifnei Hashem"?
Rashi: "mi'Lifnei Hashem" means that he took the coals from the west side of the Mizbe'ach, which was the closest to the entrance to the Kodesh.
From which Mizbe'ach did Aharon take coals for the Ketores?
Bearing in mind that all Ketores was ground fine (Dakah), why does the Torah see fit to write "Dakah" here, in connection with the Ketores on Yom Kipur?
Rashi: This teaches us that the Ketores on Yom Kipur was grounded particularly fine (Dakah min ha'Dakah). 1
Because on Erev Yom Kipur, he returned the ground Ketores to the grinder and ground it again.
Why does he interrupt with Ketores between Shechitah of the bull and sprinkling its blood? He should finish offering the bull first. We do not pass over Mitzvos!
Seforno: After he slaughtered his Chatas and said Viduy, he was free of sin, and therefore ready to receive the Shechinah, which was about to appear on the lid of the Aron, 1 It was therefore appropriate to honor the Shechinah by entering Its presence with the Ketores. 2
Riva: If he would not do the Ketores, he could not enter the Kodesh ha'Kodoshim, for the cloud of smoke must be there, lest he die.
Riva, citing R. Moshe of Pontaiza: He interrupts with Ketores, for when the cloud is there, he does not look like one who benefits from the radiance of the Shechinah.
Riva, citing R. Yosef: Had he began with sprinkling the bull's blood, he could not interrupt with the Haza'os. If after pouring the Shirayim on the Mizbe'ach he would return inside for the Ketores, this would be passing over Mitzvos.