As part of the instructions for the avodah, service on Yom Kippur, 16:16 records that Aharon was to do the same thing to the ohel moed as he did to the inner room of the mishkan. This means that he was to sprinkle blood in the ohel moed, but where exactly was he to sprinkle the blood? Rashi (on 16:16) explains that 16:16 means that Aharon was to sprinkle blood on the parochet, which was the veil that separated the two rooms of the mishkan, when Aharon was standing in the outer room of the mishkan. This explanation follows the idea that the ohel moed is the same area as the mishkan.
16:17 then records that no person was to be in the ohel moed when Aharon was in the kadosh (the inner room of the mishkan) until he left and that Aharon was to me-khapper for himself, his family, and the entire nation. Why were these instructions for the people not to be in the ohel moed recorded at this point in the description of the worship of Yom Kippur?
16:18 then records that Aharon was to purify (sprinkle blood on) the altar on Yom Kippur, but there are two altars in the ohel moed, the inner altar in the outer room of the mishkan, and the outer altar in the courtyard of the mishkan. Which altar is being referred to in 16:18?
Ibn Ezra (on 16:18) writes that 16:18 is referring to the altar in the courtyard of the mishkan. He does not provide a reason for this comment, but there are two possible reasons for this understanding. One 16:12 uses the same phrase the "altar before G-d" as in 16:18, and in 16:12 many claim (see Rashi on 16:12) that the reference is to the outer altar. However, this reason is not conclusive since it could be that in 16:12, the verse is referring to the inner altar, see our discussion above on 16:12, “Preparing the incense cloud.” Also, since both altars could be considered as being before G-d, then it could be that 16:12 is referring to the outer altar, while 16:18 is referring to the inner altar.
The second reason for understanding that 16:18 is referring to the outer altar is much more convincing. 16:18 records that Aharon was to go out to go to the altar, and the implication is that he went out of the mishkan, which means that he went out to the outer altar which was situated in the courtyard of the mishkan. If the altar being referred to in 16:18 was the inner altar, then 16:18 would have stated either that Aharon was to go into the mishkan or the verse did not have to refer to any movement from Aharon.
Notwithstanding this apparent proof from the phrase in 16:18 that “Aharon was to go out,” Chazal argue that 16:18 is referring to the inner altar, see Mishnah Yoma 5:5, Rashi on 16:18, David Hoffman on 16:18, 1953, p. 309, and Levine, 1989, p. 105. Chazal understand that the instructions for Aharon to go out in 16:18 was for him to move from the curtain that separated the two rooms in the mishkan, the parokhet, to the side of the inner altar that was near the entrance of the mishkan since then Aharon was in the process of going out of the mishkan, even if he did not actually leave. The reason why they understand 16:18 in this manner is because of Shemot 30:10, which records that the inner altar was to be purified on Yom Kippur. There is no other reference to purifying an altar in Vayikra chapter 16, hence, 16:18 must be referring to the inner altar. With this understanding, only the inner altar was purified on Yom Kippur, and not the outer altar.
Most likely, in response to the need to find the fulfillment of Shemot 30:10 in Vayikra 16, Ibn Ezra (on 16:16) writes that the phrase in 16:16 "and (Aharon) will also purify the ohel moed" means that the high priest would sprinkle blood on both the curtain in between the two rooms of the mishkan, the parochet, and on the inner altar which was in the ohel moed. Maybe Ibn Ezra's understanding is that the phrase "and the high priest will also purify the ohel moed" in 16:16 means that just as the high priest was to purify the central item on the inner room of the mishkan, the aron, so too he was to purify the central item of the outer room of the mishkan, the inner altar. According to Ibn Ezra, both of the altars were sprinkled with blood on Yom Kippur.
I do not like either approaches for several reasons. One, Ibn Ezra seems to be correct that the term going out in 16:18 means that Aharon was to leave the mishkan or some area and not just for him to go towards the exit. On the other hand, I doubt that the sprinkling of the blood in 16:16 is the fulfillment of Shemot 30:10 since due to Shemot 30:10 this was an important part of the service. This sprinkling should have been mentioned explicitly but it is not mentioned at all in 16:16.
In addition, I think the term ohel moed refers to the mishkan and the courtyard of the mishkan (see our discussions on Shemot 25:9, 27:21, “The terms mikdash, mishkan and the ohel moed in the book of Shemot” and on 1:1 “The terms mikdash, mishkan and ohel moed in the book of Vayikra”), the entire complex, and then 16:16 means that Aharon was to sprinkle blood on the courtyard of the mishkan to purify the courtyard. This could have been on the outer altar, or the curtains on the outside of the courtyard or even symbolically on the ground in the courtyard of the mishkan. 16:17 is then a warning that nobody, including priests, who usually could be in the courtyard of the mishkan, to be in the courtyard of the mishkan and certainly not in the mishkan itself, when Aharon was purifying the inner room of the mishkan.
With this understanding, when Aharon fulfilled the instructions of 16:16 to purify the ohel moed, he was not in the outer room of the mishkan to move either towards the exit or to sprinkle blood on the inner altar.
My guess is that after Aharon was to sprinkle blood in/on the courtyard of the mishkan, as recorded in 16:16, he was to go back inside the inner room of the mishkan to take out the pan with the burning coals, where he had left them in 16:13. It is never recorded when the coals were removed from the inner room of the mishkan since this was not a major part of the service, the cleaning up, but the coals had to be removed at some point since the burning coals were a fire hazard because if they were left in the inner room then a wind could cause the aron with the luchot and the mishkan to burn. It should be remembered that the mishkan was a tent structure made of wood and cloths, which could burn easily, and many times there are very strong winds in the desert, which could cause the coals to start a fire even if the structure was sturdy enough to withstand the winds. Aharon could not have removed the coals before 16:15 since he needed the coals to make a smoke cloud when he went into the inner room of the mishkan to sprinkle the blood from the hatta’t of the people. When were the burning coals removed?
According to Chazal (Mishnah Yoma 7:4), this action of removing the coals occurred after Aharon sent away the goat to Azazel, and offered his olah and the olah of the people, meaning after 16:24. With this understanding, Aharon had to switch twice into the special simple clothes for Yom Kippur since he was only able to enter the inner room of the mishkan, where the coals were located, with the special simple clothing, 16:3,4. However, the simple reading of chapter 16 is that Aharon only put on the special simple clothes once on Yom Kippur. More likely, he was to remove the burning coals before he was to remove his special clothes, which is recorded in 16:23.
My guess is that the removal of the burning coals occurred after the sprinkling of blood in 16:16, and this is hinted to in 16:17, which records that nobody should be in the ohel moed from when Aharon was to purify the inner room of the mishkan until Aharon left the inner room of the mishkan. Independent as to how one defines the term ohel moed, still this reference to Aharon leaving the inner room of the mishkan is recorded in 16:17 after Aharon had left the inner room of the mishkan to purify the ohel moed in 16:16. Why was he leaving the inner room of the mishkan again? Evidently, Aharon entered the inner room of the mishkan after he purified the ohel moed, and my guess is that this entering was to get the pan with the coals.
This understanding gives a simple explanation of the term “going out” in 16:18. The going out in 16:18 is that Aharon left the inner room of the mishkan with the coals, went to the altar in the outer room of the mishkan (and maybe put the coals on this altar), and purified the inner altar as recorded in Shemot 30:10. Later the coals could have been removed from this altar or from the room. The going out in 16:18 is then the same going out referred to in 16:17, Aharon leaving the inner room of the mishkan. The point of 16:17 is then to tell the people not to be in the ohel moed until after Aharon left the inner room of the mishkan for the last time, which was to take the coals out. Even if this action was a minor part of the ceremony of the day, nobody could be in the ohel moed until Aharon was no longer going to be in the inner room of the mishkan. With this understanding, on Yom Kippur, Aharon was to purify the inner altar of the mishkan, and maybe also the outer altar of the mishkan depending on where he sprinkled the blood in 16:16.
Vayikra 16:20 concludes the three types of sprinkling blood: First in the kodesh, the inner room of the mishkan, then in the courtyard of the mishkan/ the ohel moed and then the altar, which I believe was the inner altar in the mishkan. Possibly, the inner altar in the mishkan was purified last since the instructions to build this altar (Shemot 30:1-10) are recorded after the instructions to build all the other parts of the ohel moed, Shemot chapter 25-27, and it might have had a different purpose than the rest of the ohel moed, see our discussion on Shemot 30:1-10, “The barriers arise.” A different possible reason is that from 15:31 we see that the crucial problem of tumah in the special complex was in the mishkan, the special building, and with the order of purification suggested here, this was purified first, the kodesh, and last, the inner altar, while the courtyard was purified in between. Thus, the process of purification both began and ended with the more important areas.