A recipe of oil with spices is described which Moshe is to make and pour on the Mishkan and all its vessels, anointing them and making them holy for use.
(לא) וְאֶל־בְּנֵ֥י יִשְׂרָאֵ֖ל תְּדַבֵּ֣ר לֵאמֹ֑ר שֶׁ֠מֶן מִשְׁחַת־קֹ֨דֶשׁ יִהְיֶ֥ה זֶ֛ה לִ֖י לְדֹרֹתֵיכֶֽם׃
(א) לדרתיכם. מִכָּאן לָמְדוּ רַבּוֹתֵינוּ לוֹמַר שֶׁכֻּלּוֹ קַיָּם לֶעָתִיד לָבֹא:
(1) לדרתיכם THROUGHOUT YOUR GENERATIONS — From here our Rabbis derived that it (the oil of anointment) was miraculously preserved in its entirety for the time to come (for the Messianic days) (Horayot 11b).
(3) וחלבנה —A spice with a vile odor, called galbane [in Old French], galbanum. The Scripture counted it among the ingredients of the incense [in order] to teach us that we should not look askance at including Jewish transgressors with us when we assemble for fasting or prayer. [The Torah instructs us] that they should be counted with us. -[from Ker. 6b]
Hashem is talking about the Mishkan when all of the sudden, he says
Why does Hashem give the Mitzvah of Shabbat now?
(א) ואתה דבר אל בני ישראל. וְאַתָּה אַעַ"פִּ שֶׁהִפְקַדְתִּיךָ לְצַוּוֹתָם עַל מְלֶאכֶת הַמִּשְׁכָּן, אַל יֵקַל בְּעֵינֶיךָ לִדְחוֹת אֶת הַשַּׁבָּת מִפְּנֵי אוֹתָהּ מְלָאכָה: (ב) אך את שבתתי תשמרו. אַעַ"פִּ שֶׁתִּהְיוּ רְדוּפִין וּזְרִיזִין בִּזְרִיזוּת הַמְּלָאכָה, שַׁבָּת אַל תִּדָּחֶה מִפָּנֶיהָ: (ג) כי אות הוא ביני וביניכם. אוֹת גְּדֻלָּה הִיא בֵינֵינוּ, שֶׁבָּחַרְתִּי בָכֶם בְּהַנְחִילִי לָכֶם אֶת יוֹם מְנוּחָתִי לִמְנוּחָה: (ד) לדעת. הָאֻמּוֹת בָּהּ כי אני ה' מקדשכם:
(1) ואתה דבר אל בני ישראל SPEAK THOU ALSO UNTO THE CHILDREN OF ISRAEL —But [as for] you, although I have mandated you to command them [the Israelites] concerning the work of the Mishkan, do not let it seem to you that you may easily set aside the Sabbath because of that work. (2) אך את שבתתי תשמרו BUT NEVERTHELESS MY SABBATHS SHALL YE KEEP — Even though you be anxious and alert to do the work promptly the Sabbath nevertheless you must not set aside on its account.(3) כי אות היא ביני וביניכם FOR IT IS A SIGN BETWEEN ME AND YOU — There is a mark of distinction in the relation that exists between us, viz., the fact that I have chosen you by letting you inherit for rest that day on which “I” rested. (4) לדעת TO KNOW — (not, “for you to know”, but) for the nations of the world to know through it, כי אני ה' מקדשכם THAT I AM THE LORD THAT DOTH SANCTIFY YOU.
The next part of the Parsha is the story of the חטא העגל
Why would Ahron help them
(ב) ויבן מזבח. לִדְחוֹתָם: (ג) ויקרא חג לה' מחר. וְלֹא הַיּוֹם, שֶׁמָּא יָבֹא מֹשֶׁה קֹדֶם שֶׁיַּעַבְדוּהוּ, זֶהוּ פְּשׁוּטוֹ;
(2) ויבן מזבח HE BUILDED AN ALTAR to stall them. (3) ויקרא חג לה׳ מחר AND CALLED OUT … TO-MORROW IS A FESTIVAL TO THE LORD—But [it will] not [be] today. Perhaps Moses would come before they would worship it. This is its simple meaning.
(1) וישכימו AND THEY ROSE UP EARLY [IN THE MORNING] — Satan made them zealous in order that they might sin, (for later on in the forenoon Moses actually came down from the mountain.)
(ב) לך רד. מִגְּדֻלָּתְךָ.
(2) לך רד GO, GO DOWN from your high position;
And then finally we get the second Luchot- and Moshe has to teach all the 40 days of Torah to the rest of B’nei Yisroel
(1) ואחרי כן נגשו AND AFTERWARDS [THE CHILDREN OF ISRAEL] STEPPED NIGH — After he taught the elders, he would repeat and teach the chapter or the halachah to the Israelites. The Rabbis taught: What was the order of teaching? Moses would learn from the mouth of Almighty. Aaron would enter, and Moses would teach him his chapter. Aaron would move away and sit at Moses’ left. His [Aaron’s] sons would enter, and Moses would teach them their chapter. They would move away, and Eleazar would sit at Moses’ right and Ithamar would sit at Aaron’s left. [Then] the elders would enter, and Moses would teach them their chapter. The elders would move away and sit down on the sides. [Then] the entire nation would enter, and Moses would teach them their chapter. Thus, the entire nation possessed one [lesson from Moses], the elders possessed two, Aaron’s sons possessed three, Aaron possessed four, etc., as is stated in Eruvin (54b).