What are the connotations of the words "Kodesh" and "Tahor" in connection with the Shemen ha'Mishchah and the Ketores ha'Samim, respectively?
Seforno: "Kodesh" implies that the Shemen ha'Mishchah never deteriorated 1 and "Tahor" that the Ketores ha'Samim was free of impurities. 2
Moshav Zekenim: The Shemen ha'Mishchah is called 'Kodesh' because it is used to sanctify the Mishkan and its Keilim, and Aharon and his sons, whereas the Ketores ha'Samim is called 'Tahor' to teach that it is subject to Tum'ah 3 (through Chibas ha'Kodesh).
Why does the Torah not describe in detail how the Shemen ha'Mishchah and the Ketores ha'Samim were manufactured, as it does regarding all the other items listed in the Parshah?
Ramban: Because the Pasuk in Ki Sisa also did not specify the manufacture of the Shemen ha'Mishchah and the Ketores in detail, but left it largely to the Chachmei Leiv to duplicate the methods used by spicers of that time. 1
As the Ramban explained there (in Sh'mos 30:25 & Sh'mos 30:34), and as the Pasuk intimates here when it concludes "Ma'aseh Roke'ach" (Ramban).
