What is the exact meaning of Mizbe'ach Miktar Ketores"?
Rashi: It means a Mizbe'ach for the smoke of incense to ascend on it. 1
Targum Onkelos and Targum Yonasan: It means a Mizbe'ach to bring on it incense.
Rashbam: It also implies that it is to burn Ketores exclusively, and not Shelamim, Olos, Menachos and Nesachim. 2
Seforno: It means that the Mizbe'ach ha'Ketores only required a little fire to burn the Ketores, and that, as a result, it did not need to be hollow
Since "Miktar means a pillar of smoke. See also Sifsei Chachamim.
See Pasuk 9.
Like the Mizbe'ach ha'Olah, which was filled with earth, on which the fire burned, since the large fire that burned on it would otherwise have burned through the copper. See also Rashi on Pasuk 3 and see Torah Temimah, note 2.
See Torah Temimah, note 2.
Why did the Torah not list the Mizbe'ach ha'Ketores in Terumah (together with the Shulchan and the Menorah, as it does in Vayakhel, Sh'mos 37:25)?
Ramban and Seforno: Having concluded "ve'Nikdash bi'Chevodi. ve'Shachanti ... ", 1 the Torah now adds that there is an additional K'li that is required, on which one sacrifices the Ketores purely in order to honor Hashem, 2 as opposed to the other Keilim listed in Terumah, which were instrumental in bringing the Shechinah down to the world. 3