What is the difference between "Besamim" and "Samim"?
Ramban #1: Grammatically speaking, Besamim are edible (spices), whereas Samim are medicinal.
Ramban #2 (citing Rashi and Targum Onkelos) and Targum Yonasan: "Samim" is synonymous with Besamim. 1 However, since the Torah uses two different words to describe them, it is logical to say that Besamim are the more important spices, 2 and those with the more pungent aroma.
Ramban #3: "Besamim" is the acronym of 'Bo Samim' (it contains Samim).
Hence Onkelos (and Targum Yonasan) translate both as 'Busmaya'. And this is also the opinion of the Gemara in Kerisos, 6b (Ramban). The Ramban goes on to cite Pesukim from Shir ha'Shirim, 4:14, 16 and Vayakhel, Sh'mos 35:28, that Besamim incorporates Samim.
As is evident in Ki Sisa, Sh'mos 30:23 (Ramban).
What exactly does the Pasuk mean when it writes "ve'li'Ketores ha'Samim"?
Ramban #1: The word "ve'Samim" is missing, and it is as if the Torah had written "ve'Samim li'Ketores ha'Samim". 1
Ramban #2 (citing Ibn Ezra in the name of Chachmei ha'Dor) and Rashbam: The two words are inverted, as if the Torah had written "ve'ha'Samim li'Ketores'.
Ramban #3 (citing Ibn Ezra) and Targum Yonasan: "Besamim" refers to both the Shemen la'Ma'or and the Ketores ha'Samim. 2
Because the Ketores did contain some spices (Shiboles Nerd, Karkom and Kin'mon, as the Gemara states in Kerisos, 6a). On the other hand, the Torah does not need to mention Samim for the Ketores ha'Samim, just as it does not mention Shemen for the Shemen ha'Mishchah (Ramban).
Seeing as the Torah only lists the Keilim and their accessories, but not what was brought on them - wheat for the Lechem ha'Panim, lambs for the Korban Tamid and wood for the Ma'arachah, why does it mention the Shemen la'Ma'or, the Shemen ha'Mishchah and the Ketores?
Hadar Zekenim: It mentions the Shemen la'Ma'or, because they took from the same oil to anoint the Keilim; the Shemen ha'Mishchah, because it sanctified all the Keilim, and the Ketores, because it is the way of kings to burn fragrant spices before they enter the palace. 1
Hadar Zekeinim: The Shechinah only entered the Mishkan when the Ketores was burnt, as the Torah writes in Acarei-Mos Vayikra, 16:2 "Ki be'Anan Era'eh al ha'Kapores".
Seing as the Ketores, the oil for the Menorah and for the anointing oil are neither for the Mishkan nor for the Keilim, why are they listed?
Moshav Zekenim and Da'as Zekenim: Even though Hashem does not need the light, it is not Kavod for His house to be dark. 1
Oznayim la'Torah: All three items were necessary for the actual completion of the Mishkan: the anointing oil was needed - to anoint and to sanctify the Mishkan and its Keilim. 2 The oil for the Menorah - in order to fall in line with the Tanchuma, who compares the Mishkan to the creation - and without the oil for the Menorah, the comparison to the creation of light would be missing; and the Ketores - without which the Kohen Gadol was forbidden to enter the Kodesh Kodshim, which would therefore have been incomplete.
