In the seventh Aliyah of this week’s Parashah, Parashat Tetzaveh, the Torah describes the Mizbei’ach HaKetoret. The Mizbei'ach HaKetoret (incense altar), located in the Kodesh HaKodashim, is made of Atzei Shitim (acacia wood) and coated with pure gold. It is one cubit (19-22 inches) long, one cubit wide, and 2 cubits tall. Ketoret is offered on the Mizbei’ach once in the morning and once in the evening, and on Yom Kippur, the blood of a Chatat (sin) offering is sprinkled upon it (Shemot 30:1-10). The Mizbei'ach HaOlah, which is made of bronze and is placed in the Azarah (courtyard), is used for Korbanot (sacrifices). Why do we need two different Mizbechot? Couldn’t the Mizbei'ach HaKetoret or the Mizbei'ach HaOlah have both Ketoret and Korbanot offered upon it?
The Rambam in the Moreh Nevuchim (3:45) pragmatically explains the need for offering Ketoret, which can be used to explain the requirement for two Mizbechot. The Rambam states that there are countless numbers of Korbanot offered daily, so without the Ketoret, the Beit HaMikdash would have smelled like a butcher shop. To avoid an unpleasant odor in the Beit HaMikdash, Hashem therefore commanded the Jews to burn the Ketoret. The Beit HaMikdash is supposed to be a respected place; if there was a foul odor, the Jews would not only disrespect the Beit HaMikdash, but would even scorn it. A human is attracted to a pleasing odor, but abhors and avoids a repulsive stench. Each Mizbei’ach is needed to serve its unique purpose: the Mizbei'ach HaOlah is used to slaughter the Korbanot, while the Mizbei'ach HaKetoret ensures that the experience of the Beit HaMikdash is pleasant.
The Kli Yakar (30:1-2) takes a spiritual approach to the different purposes of the Mizbechot. The Kli Yakar explains that the two Mizbechot are used to atone for different sins: the Mizbei'ach HaOlah is used to atone for bodily sin, and the Mizbei'ach HaKetoret is used to atone for the Neshamah (soul) that is defiled by the body it inhabits. According to the Kli Yakar, man’s physical resemblance to animal adequately explains why using a sacrificial animal to atone for the body is logical. Ketoret atoning for the Neshamah is also understandable, because the smoke and fragrances of the Ketoret symbolically ascend to Hashem, just as the Neshamah ascends and descends to Hashem during the morning and the night, coinciding with the time the Ketoret is offered.
We can combine the opinions of the Rambam and the Kli Yakar to synthesize a composite explanation. The Mizbei'ach HaKetoret facilitates forgiveness for the Neshamah, and allows a person to leave the Beit HaMikdash with the recognition that Hashem still values him, even after sinning. The Korban humbles a person, as he recognizes that he should have been the sacrifice being slaughtered for his sin, but remains encouraged by how close the experience has brought him to Hashem.
With this combined approach, we can better understand the locations of the Mizbechot. The Mizbei'ach HaOlah, used to atone for the body, is placed in the outer courtyard. The Mizbei'ach HaKetoret, used to atone for the Neshamah, which is hidden inside the body, is fittingly placed in the Kodesh HaKodashim, which is hidden by the Azarah. When we sin, there are outward and inward implications, and we must repair both our actions and souls, as reflected by the structure of the Beit HaMikdash.