“And you shall make an altar for the offering of the incense” (Shemot 30:1). The placement of the mitzva to construct the mizbei’ach haketoret is striking. It is not included along with the other vessels of the Mishkan, described in Parashat Teruma, and it is found only after the mitzva of the korban tamid, where the Torah seems to conclude its discussion of the Mishkan: “I shall set My meeting there with Bnei Yisrael, and it shall be sanctified with My glory… I shall rest My presence among Bnei Yisrael and I shall be their God…” (Shemot 29:43-45).

                In this respect, the mizbei’ach hazahav is similar to the kiyor, which is also mentioned as an “afterthought” in Parashat Ki Tisa. The Gra explained that these two keilim are similar in that their absence does not preclude the avoda in the Mishkan; it is permitted to offer ketoret in the camp, and the Kohanim may wash their hands and feet with another vessel. Thus, these keilim are not part of the set structure of the Mishkan. However, this point itself demands some explanation.

                The Seforno explains:

This altar was not mention along with the other vessels in Parashat Teruma, because its purpose was not to bring about the dwelling of God in it [the Mishkan], as was the case regarding the other vessels, as the pasuk says, “And I will dwell among them”… Its purpose was also not to bring down his glory into the House, as in the case of the sacrifices… Rather, the purpose of this altar was to give honor to God after He had come to willfully accept the service of His nation…

Similarly, regarding the kiyor, Seforno writes:

This vessel was also not mentioned above along with the other vessels, because its purpose was not to bring about the dwelling of the Shechina in the Mikdash… Rather, the intent was to prepare the Kohanim for their service.

                Commenting on the pasuk, “Oil and incense gladden the heart” (Mishlei 27), Rabbeinu Bechayei (beginning of Parashat Tetzaveh) cites a midrash that interprets the pasuk as referring to the menora and the ketoret. He then writes, “Just as the Torah records the joy of HaKadosh Baruch Hu after the creation, we similarly find His joy after the building of the Mishkan.”

                We can understand this by way of a mashal. Every normal person provides his children and family members with their needs; this does not demonstrate any special affection on his part. However, one who loves another person gives extra – a candy for a child, flowers for a wife – and this extra gift expresses his love. The joy of the recipients of such gifts is greater and more overt than that of those who receive only their basic needs. It is also an efficient way to resolve conflicts and problems of shalom bayit; precisely because the gift is “extra,” it is a greater reflection of love and joy between two people, resolving difficulties. Thus, when we give Hashem the extra “gift” of the ketoret, it brings Him joy.

                Chazal tell us that one who avoids wearing a four-cornered garment, so as not to be obligated in the mitzva of tzitziit, is punished. Even though he has not violated any law, he lacks love for the mitzvos, as indicated by his failure to do anything “extra.” The ketoret is the opposite, as it expresses a person’s joy in performing the mitzvot.

It is for this reason that ketoret has the ability to stop a plague. Chazal teach that this secret was taught to Moshe Rabbeinu by the malach hamavet himself. When Moshe went up to receive the Torah, the angels were opposed, claiming that man’s physical nature prevents him from understanding lofty ideas; even after learning Torah, there is still a constant conflict between man’s physicality and his spiritual awareness. But on the highest level, man’s physicality does not interfere with his spiritual attainments, as expressed in Chazal’s statement that the malach hamavet becomes his friend. The secret that the malach hamavet shared with Moshe is that the joy that one has in doing the mitzvot is man’s innermost avoda, and this is reflected in the ketoret.

It is interesting to note that the concept of smell is used as an analogy to the tsaddikim, as it reflects purity. We further find the idea of smell in the story of the miracle of Purim: Esther’s name is also Haddassa (myrtle), and Mordechai’s name is interpreted as a reference to myrrh (as mor deror is translated by the Targum as mari dachya). Along with Chanuka, the other holiday that was added by Chazal, Purim reflects Hashem’s happiness with Yisrael and vice versa. 

In the Moreh Nevuchim, the Rambam writes that the purpose of the ketoret was to remove the foul smells in the Mikdash, which resulted from the meat of the korbanot. It seems that he reached this conclusion as a result of our original question regarding the fact that the ketoret seems to be mentioned as an afterthought. He therefore explained that the ketoret was not integral to the avoda, but rather a peripheral matter. However, this explanation is difficult to accept given the stringency of the laws regarding this mitzva.

Perhaps we can suggest that creating a pleasant smell is symbolic, as well as practical. Smell is considered a manner of determining the true nature of something. Thus, in every language, when something appears to be negative but cannot be proven to be, we say that “it smells rotten.” Thus, Chazal tell us that we will perceive the Mashiach by his smell, as he will achieve perfect attainment of truth. Similarly, Hashem’s joy in this world is defined by smell. Since reality is also made up of negative things, creating bad smells, creation of good smells is symbolic of the fact that good is overpowering evil. For this reason, the avoda of the ketoret is given special importance.

Similarly, the kiyor – although it was not necessary for the avoda itself – provided depth and meaning to the avoda through its symbolism. The Kohanim prepared themselves for the avoda through a vessel that was constructed not from the general donation, but rather from the donation of the “mar’ot hatzov’ot” – the women’s desire to give their copper mirrors to the Mishkan. Rashi explains that these mirrors had been used for holy purposes, as the women had beautified themselves in Egypt in order to maintain normal family life, despite the efforts of the Egyptians. Thus, these mirrors symbolized the sanctity of family life. These women merited that the waters given the sota are taken from the kiyor that they helped construct, declaring that their relationships with their husbands were pure and holy, and thereby teaching all generations how it is possible to live a life of sanctity while still benefiting from this world.

Thus, the construction of the mizbei’ach haketoret and they kiyor teaches us about the importance of two central values – preparing properly for a mitzva and performing it with joy.