Why does the Torah mention here that “six days you shall do work”?
(35,1) “And Moshe assembled all the congregation of the Children of Yisrael, and said to them: These are the things which Hashem has commanded to do. Six days you shall do work, but on the seventh day it will be holy for you, a Shabbos of rest to Hashem. Anyone who does work on it shall be put to death. You shall not light a fire in any of your dwelling places on the Shabbos day.”
Why does the Torah mention doing work during the six days of the week in connection with the command of keeping Shabbos? And why does it say תעשה in the singular, rather than the plural תעשו?
We can explain these posukim according to the gemora Shabbos 49b which teaches that the thirty-nine categories of work that are forbidden on Shabbos correspond to the thirty-nine categories of work that were performed in the building of the Mishkan, meaning that any work that was performed in the making of the Mishklan is forbidden on Shabbos. But why is this so - why are the laws of Shabbos dependent on what was done when they made the Mishkan?
But we know that the making of the Mishkan is comparable to the creation of the world, and the creation of the world was also done with these thirty-nine categories of work, and on Shabbos Hashem rested. Therefore, Hashem commanded us to also refrain from these categories of work on Shabbos.
This is the explanation of the posukim: “אלה הדברים (These are the things)” - the gemora Shabbos 70a teaches that these two words allude to the number of categories of work which are forbidden on Shabbos, and from where are these forbidden things derived? From that “which Hashem has commanded to do” - the making of the Mishkan. Thus the forbidden labors of Shabbos correspond to the work done in the making of the Mishkan. And from where is the fact that Shabbos is dependent on the Mishkan derived? From the “six days” of creation when “work was done” by itself by the command of Hashem, and on the seventh day He rested. Therefore, “the seventh day shall be holy to you, a Shabbos of rest to Hashem”.
And this is why of all the thirty-nine categories of work only the command “you shall not light a fire” is written here, because this corresponds to the first command of Hashem when He created the world - “let there be light”, and all the other categories of work can be learned from this first one.
And this answers a difficulty that various commentaries have asked on the Mishnah in Shabbos 73a which says that “the principle categories of work are forty minus one”. Surely it should say thirty-nine! But it makes sense according to our explanation that these forbidden labors are derived from the creation of the world, because there were in fact forty acts of creation. Because why does it say (Bereishis 2,2) “and G-d finished on the seventh day”? It should say the sixth day! Rashi answers: What was the world lacking? Rest. When Shabbos came, rest came, and thus on the seventh day the work of creation was finished. From this we see that rest - the ability to rest - was also an act of creation.
Thus there are in fact forty main categories of work, but the Mishnah says forty minus one because only thirty-nine are forbidden, but the fortieth is a positive command - to rest.
The son of the author adds that the gematria of the first letters of the words from בראשית until ובהו, excluding the word תהו, add up to thirty-nine. And the gematria of the word תהו is 411 which alludes to the Beis Hamikdash itself which stood for 410 years and thus destroyed in the 411th year, as the Ba’al HaTurim writes in the beginning of parshas Bereishis. And the gemora in Eruvin 2a teaches that the משכן is called מקדש, and the מקדש is called משכן.
Thus we can explain that the reason why the word תהו interrupts the gematria of thirty-nine is to teach us that even though building the Mishkan and the Beis Hamikdash does not override the laws of Shabbos, the sacrifices which are offered there do override Shabbos.
Why did Moshe not simply command the people to stop bringing items for the building of the Mishkan?
(36,5) “And they spoke to Moshe, saying: The people are bringing more than is needed for the work of the service which Hashem commanded to do. So Moshe commanded that they proclaim throughout the camp, saying: Let no man or woman do any more work for the holy donation. And the people stopped bringing.”
Why did Moshe not simply say "Let no man or woman bring any more for the holy donation"?
But the gemora in Ta’anis 23a teaches that a person should not pray concerning an abundance of good. Thus Moshe was not able to proclaim not to bring any more since this would be a refusal to accept an abundance of good. Therefore he commanded that they proclaim that they not do any more work, and thus it would automatically follow that “the people stopped bringing”.
Why does the Torah say that the work was sufficient for the needs of the Mishkan, and also that it was more than was necessary?
(36,7) “And the work was sufficient for all the work that needed to be done, and even more than sufficient.”
This posuk seems somewhat contradictory, because first it says that the “work was sufficient”, but then it says that it was “more than sufficient”!
But the explanation is that Hashem commanded Yisrael to do more than was sufficient, because a person is supposed to give generously. Thus the posuk means that “the work was sufficient” to fulfil Hashem's command, that is, “it was sufficient” and “even more than sufficient”.