Seeing as they were about to build the Mishkan (as the Torah refers to it in Pasuk 9), why does it refer to it here as "Mikdash"?
Rashi: It means that Yisrael should construct a 'holy house' for Hashem.
Rashbam: "Mikdash" has connotations of meeting - It is a location where Hashem will meet them to communicate with them. 1
Shevu'os, 16b: From here we see that the Mishkan is also called Mikdash. 2
Why does the Torah add the (otherwise superfluous) word "Ve'asu Li Mikdash"?
Rashi and Targum Yonasan: To teach them that they should build the Mishkan specifically in the Name of Hashem.
Temurah, 31a: To teach us that one pays the laborers of Hekdesh with the funds of Bedek ha'Bayis - with money that belongs to Hashem. 1
Temurah (Ibid.): As if the Torah had written "mi'she'Li".
How will we reconcile this Pasuk with the Pasuk in Beshalach, 15:17 "Tevi'eimo ve'Ta'eimo be'Har Nchalascha ... ", which implies that they would only build the Beis ha'Mikdash once they arrived in Eretz Cana'an"?
Kesuvos, 62b: The Pasuk teaches us how precious Yisrael are to Hakadosh-Baruch-Hu - that Kevayachol, He could not wait so long to come and dwell in Yisrael's midst, so He commanded them to build it already now.
