The splendid turbans. Rashi needed to explain this so we will not mistakenly think that פארי means as it does in, “He will cut the branches ( פארה ) with terror” (Yeshaya10:33). Thus Rashi explains that it means, “The splendor of the turbans.” פארי is the plural of פאר , and means the same as פארים (splendors). Rashi says, “The splendid turbans,” because if the turbans were not splendid, there would not be any פארים [at all, since פארים is not an object that stands on its own] — and in that case it would not say פארי המגבעות .

The work. Rashi adds the phrase, “The work,” to inform us what B’nei Yisrael did. For it is written [just before], “Thus was completed all the work of the mishkon.” If so, they surely did the work [already], so what does it mean that they “did”? Therefore, Rashi explains, “The work.” The verse is conveying that the work they did was not any different, but rather they did it just as God commanded Moshe.

For they were unable to erect it . . . [Rashi knows this] because otherwise, they would not have brought it [to Moshe] in pieces, since it is the way of craftsmen to erect a house and then to show what they built. Therefore Rashi explains, “For they were unable to erect it.” Rashi then answers a further question: Every time they traveled from place to place, they erected the mishkon[themselves]. If so, why did they not do so now as well? Therefore Rashi explains, “Because Moshe did no work. . ..” Thus the first time, it was erected through Moshe, of its own. And from then on, each time they traveled, it stood upright on its own, and through those who erected it. (Nachalas Yaakov) Here it is implied that even Moshe erected it [only] by a miracle. But in Shabbos 92a, Berachos 54b and Bechoros 44a, it is implied that since Moshe was ten amohs tall, he therefore had the strength to erect it. See there.

May the pleasantness . . . Rashi is answering the question: What blessing did Moshe give them? Therefore Rashi explains that it was the blessing of ויהי נועם , which Moshe composed upon the completion of the building of the mishkon.

This is one of the eleven Psalms . . . It seems that Rashi needed to bring this as proof [that Moshe blessed them with ויהי נועם ] because [one opinion] in Sifra ch.1 says that they [the people] said ויהי נועם to Moshe. Similarly in Yalkut Shimoni, Pekudei 418. (Nachalas Yaakov)