רמב"ן - 30:1 “ועשית מזבח מקטר קטרת עצי שטים תעשה אתו”
“You shall make a Mizbe’ach on which to bring incense up in smoke, of shittim wood shall you make it.” The last of the Mishkan’s Keilim is the Mezbe’ach upon which incense was burned every morning and evening. It was known as the Mizbach Haktores, the Mizbach Hazahav, and the Mizbach Hapnimi. Why is the Mizbe’ach not mentioned earlier together with the Menorah and the Shulchan, the Keilim that were near it in the Mishkan? The function of the Mizbach Hazahav was completely different from the function of the Mishkan as a whole. The Mishkan provided an appropriate setting for Hashem to rest His Shechina upon Klal Yisroel. However, Hakodosh Boruch Hu being close, sets up the potential situation which is very dangerous for those who do not honor His Presence properly. They would be subject to the Midas Hadin, and may be punished harshly for their actions. This was the case with Nadav and Avihu, who lost their lives when they brought a Korbon that was not commanded to be brought, and therefore forbidden. For this, Hakodosh Boruch Hu provided a means to shelter Klal Yisroel from such potential danger. When this Korbon was brought by the bidding of Hashem, incense has the unique ability to stave off the wrath that may have otherwise been inflicted for actions that should not have been performed. Being that the Shechina was now prepared to rest in the Mishkan, and that meant that the Shechina would be nearby, thus a different amount of respect was warranted. There was now a need for this Mizbe’ach, for Ketores to be brought to save Klal Yisroel from being harshly punished for their infractions against the Kovod of the Shechinah.
